Patient Characteristics Associated With Quality of Colonoscopy Preparation: A Systematic Review and Meta-analysis

Impact of inadequate bowel cleansing in sigmoidoscopy screening

BACKGROUND AND STUDY AIMS

Long-time follow-up of sigmoidoscopy screening trials has shown reduced incidence and mortality of colorectal cancer (CRC), but inadequate bowel cleansing may hamper efficacy. The aim of this study was to assess the impact of bowel cleansing quality in sigmoidoscopy screening.

PATIENTS AND METHODS

Individuals 50 to 74 years old who had a screening sigmoidoscopy in a population-based Norwegian, randomized trial between 2012 and 2019, were included in this cross-sectional study. The bowel cleansing quality was categorised as excellent, good, partly poor, or poor. The effect of bowel cleansing quality on adenoma detection rate (ADR) and referral to colonoscopy was evaluated by fitting multivariable logistic regression models.

RESULTS

35,710 individuals were included. The bowel cleansing at sigmoidoscopy was excellent in 20,934 (58.6%) individuals, good in 6580 (18.4%), partly poor in 7097 (19.9%) and poor in 1099 (3.1%). The corresponding ADRs were 17.0%, 16.6%, 14.5%, and 13.0%. Compared to participants with excellent bowel cleansing, those with poor bowel cleansing had an odds ratio for adenoma detection of 0.66 (95% confidence interval 0.55-0.79). We found substantial differences in the assessment of bowel cleansing quality among endoscopists.

CONCLUSIONS

Inadequate bowel cleansing reduces the efficacy of sigmoidoscopy screening, by lowering ADR. A validated rating scale and improved bowel preparation are needed to make sigmoidoscopy an appropriate screening method.

Trial registration Clinicaltrials.gov (NCT01538550).

One-day versus three-day low-residue diet bowel preparation regimens before colonoscopy: a meta-analysis of randomized controlled trials

BACKGROUND AND AIM

Although studies have shown that the quality of bowel preparation with low-residue diet (LRD) is as effective as that of clear fluid diet (CLD), there is currently no consensus on how long an LRD should last. The aim of this study was to compare a 1-day versus 3-day LRD on bowel preparation before colonoscopy.

METHODS

A systematic review search was conducted in MEDLINE/PubMed, EMBASE, Web of Science, and Cochrane database from inception to April 2023. We identified randomized controlled trials (RCTs) that compared 1-day with 3-day LRD bowel cleansing regiments for patients undergoing colonoscopy. The rate of adequate bowel preparation, polyp detection rate, adenoma detection rate, tolerability, willingness to repeat preparation, and adverse events were estimated using odds ratios (OR) and 95% confidence interval (CI). We also performed meta-analysis to identify risk factors and predictors of inadequate preparation.

RESULTS

Four studies published between 2019 and 2023 with 1927 participants were included. The present meta-analysis suggested that 1-day LRD was comparable with 3-day LRD for adequate bowel preparation (OR 0.89; 95% CI, 0.65-1.21; P = 0.45; I2 = 0%; P = 0.52). The polyp detection rate (OR 0.94; 95% CI, 0.77-1.14; P = 0.52; I2 = 23%; P = 0.27) and adenoma detection rate (OR 0.87; 95% CI, 0.71-1.08; P = 0.21; I2 = 0%; P = 0.52) were similar between the groups. There were significantly higher odds of tolerability in patients consuming 1-day LRD compared with 3-day LRD (OR 1.64; 95% CI, 1.13-2.39; P < 0.01; I2 = 47%; P = 0.15). In addition, constipation was identified as the independent predictor of inadequate preparation (OR 1.98; 95% CI, 1.27-3.11; P < 0.01; I2 = 0%; P = 0.46).

CONCLUSION

The present study demonstrated that a 1-day LRD was as effective as a 3-day CLD in the quality of bowel preparation before colonoscopy and significantly improved tolerability of patients. In addition, constipation is an independent risk factor of poor bowel preparation, and the duration of LRD in patients with constipation still needs further clinical trials.

Colonoscopy Utilization in Elderly Patients with Dementia: Characteristics, Complications, and Charges in a National Matched-Cohort Analysis

BACKGROUND

It is projected that the elderly population will continue to increase. Many will develop chronic conditions such as dementia.

AIMS

Our aims are to describe the utilization of colonoscopy among patients with dementia and compare outcomes in those with and without dementia.

METHODS

This population-based analysis utilized the National Inpatient Sample (NIS) during 2019. Patients with dementia over the age of 60 years receiving colonoscopy were identified utilizing ICD-10 codes. Logistic regression was used for propensity score matching between the comparison groups. A Greedy one-to-one matching algorithm was utilized along with standardized mean differences to assess balance. Mcnemar test, signed rank sum, and paired t-test were used to compare the outcomes.

RESULTS

Initially, 50,692 patients without dementia were compared with 4323 patients with dementia. Patients with dementia were more likely to be female, older, less likely White, had lower income, and more likely to be on Medicare. In the matched comparison (4176 in each group), complication analysis showed that patients with dementia did not have higher colonoscopy-related complications. They did have higher rates of other complications including renal/AKI (p = 0.0042), pulmonary/pneumonia (p = 0.003), cerebrovascular accidents (p = 0.0063), and sepsis (< 0.0001). Patients with dementia were also less likely to have routine discharges (< 0.0001), had longer hospital stays (< 0.0001), and higher hospital costs (< 0.0001).

CONCLUSIONS

Elderly patients with dementia have similar colonoscopy-related complications as patients without dementia. However, they do have higher complications in general. The decision whether to perform colonoscopy in this patient population is multifactorial. A careful assessment of a dementia patient's history can help with this decision.

Risk factors for inadequate bowel preparation before colonoscopy: A meta-analysis

OBJECTIVE

This meta-analysis aimed to comprehensively explore the risk factors for inadequate bowel preparation (IBP).

METHODS

We searched the Embase, PubMed, Web of Science, and The Cochrane Library databases up to August 24, 2023, to identify observational studies and randomized controlled trials (RCTs) that examined risk factors for IBP. A random effects model was used to pool the adjusted odds ratios and 95% confidence intervals.

RESULTS

A total of 125 studies (91 observational studies, 34 RCTs) were included. Meta-analyses of observational studies revealed that three preparation-related factors, namely, characteristics of last stool (solid or brown liquid), incomplete preparation intake, and incorrect diet restriction, were strong predictors of IBP. The other factors were moderately correlated with IBP incidence, including demographic variables (age, body mass index, male sex, Medicaid insurance, and current smoking), comorbidities (diabetes, liver cirrhosis, psychiatric disease, Parkinson's disease, previous IBP, poor mobility, inpatient, and Bristol stool form 1/2), medications (tricyclic antidepressants, opioids, antidepressants, narcotics, antipsychotics, and calcium channel blockers), and preparation-related factors (preparation-to-colonoscopy interval not within 3 to 5/6 h, nonsplit preparation, and preparation instructions not followed). No colonoscopy indications were found to be related to IBP. Meta-analyses of RCTs showed that education, constipation, stroke/dementia, and discomfort during preparation were also moderately associated with IBP. Most of the other findings were consistent with the pooled results of observational studies. However, primarily due to imprecision and inconsistency, the certainty of evidence for most factors was very low to moderate.

CONCLUSIONS

We summarized five categories of risk factors for IBP. Compared to demographic variables, comorbidities, medications, and colonoscopy indications, preparation-related elements were more strongly associated with IBP. These findings may help clinicians identify high-risk individuals and provide guidance for IBP prevention.

Timely Completion of Direct Access Colonoscopy Is Noninferior to Office Scheduled for Screening and Surveillance

GOALS

We aimed to evaluate whether direct access colonoscopy (DAC) is noninferior to office-scheduled colonoscopy (OSC) for achieving successful colonoscopy.

BACKGROUND

DAC may improve access to colonoscopy. We developed an algorithm assessing eligibility, risk for inadequate preparation, and need for nursing/navigator assistance.

STUDY

This was a retrospective, single-center study of DAC and OSC patients from June 5, 2018, to July 31, 2019. Patients were 45 to 75 years old with an indication of screening or surveillance. A successful colonoscopy met 3 criteria: complete colonoscopy (cecum, anastomosis, or ileum), adequate preparation (Boston Score ≥2/segment), and performed <90 days from initial patient contact. Unsuccessful colonoscopy did not meet ≥1 criteria. Secondary end points included days to successful colonoscopy, preparation quality, polyp detection, and 10-year recall rate. Noninferiority against risk ratio value of 0.85 was tested using 1-sided alpha of 0.05.

RESULTS

A total of 1823 DAC and 828 OSC patients were eligible. DAC patients were younger, with a greater proportion of black patients and screening indications. For the outcome of successful colonoscopy, DAC was noninferior to OSC (DAC vs. OSC: 62.7% vs. 57.1%, RR 1.16, 95% LCL 1.09, P=0.001). For DAC, days to colonoscopy were fewer, and likelihood of 10-year recall after negative screening greater. Boston Score and polyp detection were similar for groups. Black patients were less likely to achieve successful colonoscopy; otherwise, groups were similar. For unsuccessful colonoscopies, proportionally more DAC patients canceled or no-showed while more OSC patients scheduled >90 days. DAC remained noninferior to OSC at 180 days.

CONCLUSIONS

DAC was noninferior to OSC for achieving successful colonoscopy, comparing similarly in quality and efficiency outcomes.

Development and validation of a novel scoring system based on a nomogram for predicting inadequate bowel preparation

BACKGROUND AND AIMS

Adequate bowel preparation (BP) is crucial for the diagnosis of colorectal diseases. Identifying patients at risk of inadequate BP allows for targeted interventions and improved outcomes. We aimed to develop a model for predicting inadequate BP based on preparation-related factors.

METHODS

Adult outpatients scheduled for colonoscopy between May 2022 and October 2022 were enrolled. One set (N = 913) was used to develop and internally validate the predictive model. The primary predictive model was displayed as a nomogram and then modified into a novel scoring system, which was externally validated in an independent set (N = 177). Inadequate BP was defined as a Boston Bowel Preparedness Scale (BBPS) score of less than 2 for any colonic segment. The model was evaluated by the receiver operating characteristic (ROC) curve, calibration plots, and decision curve analysis (DCA).

RESULTS

Independent factors included in the prediction model were stool frequency ≤ 5 (15 points), preparation-to-colonoscopy interval ≥ 5 h (15 points), incomplete dosage (100 points), non-split dose (90 points), unrestricted diet (88 points), no additional water intake (15 points), and last stool appearance as an opaque liquid (0-80 points). The training set exhibited the following performance metrics for identifying BP failure: area under the curve (AUC) of 0.818, accuracy (ACC) of 0.818, positive likelihood ratio (PLR) of 2.397, negative likelihood ratio (NLR) of 0.162, positive predictive value (PPV) of 0.850, and negative predictive value (NPV) of 0.723. In the internal validation set, these metrics were 0.747, 0.776, 2.099, 0.278, 0.866, and 0.538, respectively. The external validation set showed values of 0.728, 0.757, 2.10, 0.247, 0.782, and 0.704, respectively, indicating strong discriminative ability. Calibration curves demonstrated close agreement, and DCA indicated superior clinical benefits at a threshold probability of 0.73 in the training cohort and 0.75 in the validation cohort for this model.

CONCLUSIONS

This novel scoring system was developed from a prospective study and externally validated in an independent set based on 7 easily accessible variables, demonstrating robust performance in predicting inadequate BP.

Sex Difference of Colon Adenoma Pathway and Colorectal Carcinogenesis

Colorectal cancer (CRC) is one of the most common causes of cancer morbidity in both sexes but shows sex differences. First, sex-specific differences in tumor recurrence and survival rates have been reported. For example, the development of CRC is found about 1.5 times higher and 4-8 years earlier in males compared to females, suggesting the protective role of estrogen in the disease. Furthermore, female patients have a higher risk of developing right-sided (proximal) colon cancer than male patients, which is known to have more aggressive clinical character compared to left-sided (distal) colon cancer. That is, left and right CRCs show differences in carcinogenic mechanism, that the chromosomal instability pathway is more common in left colon cancer while the microsatellite instability and serrated pathways are more common in right colon cancer. It is thought that there are sex-based differences on the background of carcinogenesis of CRC. Sex differences of CRC have two aspects, sexual dimorphism (biological differences in hormones and genes) and gender differences (non-biological differences in societal attitudes and behavior). Recently, sex difference of colon adenoma pathway and sexual dimorphism in the biology of gene and protein expression, and in endocrine cellular signaling in the CRC carcinogenesis have been accumulated. In addition, behavioral patterns can lead to differences in exposure to risk factors such as drinking or smoking, diet and physical activity. Therefore, understanding sex/gender-related biological and sociocultural differences in CRC risk will help in providing strategies for screening, treatment and prevention protocols to reduce the mortality and improve the quality of life. In this review, sex/gender differences in colon adenoma pathway and various aspects such as clinicopathological, biological, molecular, and socio-cultural aspects of CRC were described.

Individualized intervention based on a preparation-related prediction model improves adequacy of bowel preparation: A prospective, multi-center, randomized, controlled study

AIMS

An easy-to-use preparation-related model (PRM) predicting inadequate bowel preparation (BP) was developed and proved superior to traditional models in our previous study. Here we aimed to investigate whether PRM-based individualized intervention can improve BP adequacy.

METHODS

Patients undergoing morning colonoscopy were prospectively enrolled in 5 endoscopic centers in China. After standard BP of split-dose polyethylene glycol (PEG) was completed, patients were randomized (1:1) to the individualized group or standard group. High-risk patients predicted by PRM score ≥3 were instructed to drink an additional 1.5 L PEG in the individualized group while not in standard group. The primary endpoint was the rate of adequate BP, defined by segmental Boston bowel preparation scale ≥2. Secondary outcomes included adenoma detection rate (ADR) and adverse events.

RESULTS

900 patients were randomly allocated to the individualized group (n = 449) and the control (n = 451). Baseline characteristics were similar between the two groups. The rates of high-risk patients were 19.6 % in individualized group and 19.7 % in standard group. In intention-to-treat analysis, adequate BP was 91.8 % in individualized group and 84.7 % in the standard group (p = 0.001). Among high-risk patients, adequate BP rate was 94.3 % in individualized group and 49.3 % in standard group (p < 0.001), and ADR were 40.9 % vs 16.9 %, respectively (p < 0.001). No significant differences were found regarding the adverse events and willingness to repeat BP (all p >0.05).

CONCLUSIONS

The individualized intervention using an additional dose of PEG to high-risk patients predicted by PRM, significantly improved BP quality. The intervention significantly improved ADR in high-risk patients. (ClinicalTrials.gov number: NCT04434625).

Predictors of inadequate bowel preparation in older patients undergoing colonoscopy: A systematic review and meta-analysis

BACKGROUND

Factors that predict the quality of bowel preparation in older adults are unclear, and current guidelines do not provide specific recommendations.

OBJECTIVE

This meta-analysis aimed to identify risk factors for inadequate bowel preparation in older patients.

METHODS

PubMed, Embase, Web of Science, China National Knowledge Infrastructure (CNKI), Wanfang, and VIP databases were searched from their inception to February 2023. Cohort and cross-sectional studies exploring the risk factors for inadequate bowel preparation were included in this systematic review. Odds ratio (OR) values from individual studies were pooled using fixed-effects and random-effects models. In addition, a sensitivity analysis and assessment of publication bias were performed.

RESULTS

This meta-analysis included six studies (n = 1553) on previous abdominal surgery, six studies (n = 1494) on constipation, seven studies (n = 1505) on diabetes, eight studies (n = 2093) on non-compliance with the diet regimen, seven studies (n = 1350) on incomplete intake of laxative, and nine studies (n = 2163) on inadequate exercise during preparation. The pooled analysis showed that history of abdominal surgery (OR = 2.72; 95 % confidence interval, CI: 2.07 to 3.56), constipation (OR = 3.56, 95 % CI: 2.41 to 5.25), diabetes (OR = 2.54, 95 % CI: 1.81 to 3.57), non-compliance with the diet regimen (OR = 2.51, 95 % CI: 1.96 to 3.21), incomplete intake of laxative (OR = 2.43, 95 % CI: 1.60 to 3.67), and inadequate exercise during preparation (OR = 3.13, 95 % CI: 2.39 to 4.11) were independent risk factors for inadequate bowel preparation in older patients undergoing colonoscopy.

CONCLUSIONS

Three comorbid factors and three behavioral factors were significantly associated with inadequate bowel preparation in older adults. This meta-analysis provides valuable information for developing predictive models of poor bowel preparation.

Models and scores to predict adequacy of bowel preparation before colonoscopy

Adequate bowel preparation is of paramount importance for the effectiveness of preventive colonoscopy as it allows visualization of the mucosal surface and adenomas detection, the pre-malignant lesions leading to colon cancer. Still, a considerable portion of patients fail to achieve adequate bowel cleansing, with predictors of inadequate bowel preparation being at the focal point of several studies, so far. Incorporation of these factors within predictive models has been implemented in an effort to promptly identify patients at risk for inadequate bowel preparation and thus, timely adopt practices that have the potential to improve bowel cleansing. Ultimately, this could lead to improved procedural outcomes not only in terms of neoplastic detection rate but also interval repeat procedures, expenses, patient convenience and adverse events risk. Aim of this manuscript is to present an up to date overview of all predictive scores/models addressing bowel cleansing adequacy in everyday clinical practice.

Importance of Bowel Habits in Predicting Inadequate Bowel Preparation: A Prospective Observational Study

OBJECTIVES

Inadequate bowel preparation (BP) negatively affects the efficacy and quality of colonoscopy. Although constipation has already been reported as one of the most important predictors of inadequate BP, there is limited information on the relation between inadequate BP and bowel habits including constipation-related symptoms, medications, and severity of constipation.

METHODS

This single-center, prospective observational study was conducted between August 2019 and May 2020. All participants answered questionnaires regarding personal bowel habits and received low-volume polyethylene glycol plus ascorbic acid for outpatient colonoscopy. Severity of constipation was evaluated by constipation scoring system. Bowel preparation cleansing was evaluated using Boston Bowel Preparation Scale (BBPS). Potential predictors of inadequate BP were analyzed using multivariate logistic regression models.

RESULTS

Overall, 1054 patients were enrolled, of which, 105 (10%) had inadequate BP (total BBPS ≤ 6 or any segmental BBPS < 2). The risk of inadequate BP increased with constipation severity (P = 0.01). Multivariate analysis showed that frequent straining (> 25% of defecations) (OR 2.09, 95% CI: 1.33-3.28) and chronic use of stimulant laxatives (OR 2.57, 95% CI: 1.59-4.17) were significant predictors of inadequate BP, among personal bowel habits.

CONCLUSION

Frequent straining and chronic use of stimulant laxatives were predictors of inadequate BP. An intensified preparation regimen should be considered for severely constipated patients with straining and chronic use of stimulant laxatives.

Colon Bowel Preparation in the Era of Artificial Intelligence: Is There Potential for Enhancing Colon Bowel Cleansing?

BACKGROUND AND OBJECTIVES

Proper bowel preparation is of paramount importance for enhancing adenoma detection rates and reducing postcolonoscopic colorectal cancer risk. Despite recommendations from gastroenterology societies regarding the optimal rates of successful bowel preparation, these guidelines are frequently unmet. Various approaches have been employed to enhance the rates of successful bowel preparation, yet the quality of cleansing remains suboptimal. Intensive bowel preparation techniques, supplementary administration of bowel solutions, and educational interventions aimed at improving patient adherence to instructions have been commonly utilized, particularly among patients at a high risk of inadequate bowel preparation. Expedited strategies conducted on the same day as the procedure have also been endorsed by scientific organizations. More recently, the utilization of artificial intelligence (AI) has emerged for the preprocedural detection of inadequate bowel preparation, holding the potential to guide the preparation process immediately preceding colonoscopy. This manuscript comprehensively reviews the current strategies employed to optimize bowel cleansing, with a specific focus on patients with elevated risks for inadequate bowel preparation. Additionally, the prospective role of AI in this context is thoroughly examined.

CONCLUSIONS

While a majority of outpatients may achieve cleanliness with standard cleansing protocols, dealing with hard-to-prepare patients remains a challenge. Rescue strategies based on AI are promising, but such evidence remains limited. To ensure proper bowel cleansing, a combination of strategies should be performed.

A Systematic Review of Exercise Therapy for Bowel Preparation: Evidence to Guide Practice

This systematic review aims to evaluate (1) the effectiveness of exercise therapy in bowel preparation for colonoscopy, and (2) the characteristics of exercise programs for bowel preparation. Systematic searches were done in PubMed, EMBASE, the Cochrane Library, Web of Science, and CINAHL from inception to November 2022. Randomized controlled trials and quasi-experimental studies assessing the efficacy of exercise during bowel preparation were included in this review. Two reviewers independently assessed the methodological quality using a modified Downs and Black checklist. A narrative synthesis was conducted. A total of five studies (1,109 participants) were included in this review. In all eligible studies, the characteristics of the exercise programs varied and included mainly two types of exercise (walking and yoga), various amount of exercise (3,000-10,000 steps or 0.5-1.9 hours), and two exercise timing (during and 1 hour after taking the laxative). Available evidence indicated that exercise therapy is effective in improving the quality of bowel preparation. However, there was insufficient high-quality evidence to conclude the effects on procedure-related indicators, adverse events, and willingness to repeat preparation. Exercise should be recommended as an important part of routine bowel preparation for patients undergoing colonoscopy to improve the quality of bowel preparation. More rigorous studies focusing on the effects on procedure-related indicators, adverse events, and willingness to repeat preparation are needed. To ensure the effectiveness and safety of the intervention, it is critical to establish a standard, well-structured exercise program for bowel preparation.

Bowel cleansing effectiveness and safety of 1L PEG + Asc in the real-world setting: Observational, retrospective, multicenter study of over 13000 patients

Background and study aims Effective bowel cleansing is critical for detecting lesions during colonoscopy, highlighting the importance of bowel preparations. 1L polyethylene glycol (PEG) + ascorbate (Asc) is the only recommended 1L PEG product in Europe and the United States. Its efficacy was demonstrated in large-scale controlled trials and confirmed in smaller-scale real-world studies. However, no large-scale real-world data exist. Patients and methods This observational, retrospective, multicenter study, used outpatient follow-up data from medical records from 10 centers in Spain and two in Portugal. Outpatients aged ≥18 years using 1L PEG + Asc as bowel preparation were included. The main outcome measures were overall adequate colon cleansing (Boston Bowel Preparation Scale [BBPS] score ≥6 with BBPS score ≥2 in each segment) and high-quality cleansing of the right colon (BBPS score=3). Results Data from 13169 eligible patients were included. Overall cleansing success was achieved in 89.3% (95%CI 88.7%-89.8%) and high-quality cleansing in the right colon in 49.3% (95%CI 48.4%-50.2%) of patients. For the overnight split-dose and same-day regimens, overall adequate quality cleansing success rate was 94.7% and 86.7% ( P <0.0001) and high-quality cleansing of the right colon rate was 65.4% and 41.4% ( P <0.0001), respectively. Colonoscopy was completed in 97.3% of patients, with non-completion due to poor preparation in only 0.8%; 2.3% of patients experienced at least one adverse event (AE). Conclusions This large-scale, real-world study demonstrates the effectiveness of 1L PEG + Asc in the total and right colon, with a low percentage of patients with AEs in routine clinical practice.

Visualization analysis of research on pre-colonoscopy bowel preparation

BACKGROUND

Bowel preparation is an essential step before colonoscopy, and its research topics are relatively scattered. Understanding the research status and development trend of bowel preparation is of great value for disease research and actual clinical work. However, there is currently a lack of research in this field in the form of bibliometrics.

AIM

To understand the research hotspots and development trends of bowel preparation during colonoscopy around the world.

METHODS

The literature about the topics of bowel preparation was retrieved from the CNKI, Wanfang, VIP, China Biomedical Literature Database (CBM), and Web of Science core datasets from the inception of the database to September 10, 2022. CiteSpace 6.1. R3 was used to visually analyze the annual number of publications, countries, institutions, authors, keywords, clusters, and co-citation literature.

RESULTS

A total of 2340 Chinese and 2574 English publications were included, and the number of annual publications showed an increasing trend from year to year. The author with the largest number of publications worldwide was Hassan Cesare, and the most productive countries included USA, Korea, UK, Italy, and China. Meng Xiao-Fen, Zhang Yuan-Yuan, and Niu Mei-E were the China's most prolific authors. The First Affiliated Hospital of Suzhou University, the General Hospital of the Chinese People's Liberation Army, and the Second Affiliated Hospital of Xi'an University were the most prolific institutions. Research hotspots focused on the quality of bowel preparation, the design of bowel preparation programs, and special groups for bowel preparation.

CONCLUSION

Studies related to bowel preparation have certain foundations, and China's research can follow international hotspots, but cooperation among countries still needs to be strengthened. We should expand the research output related to bowel preparation based on a broader population and more suitable for the development of the era of big data, to provide higher quality research evidence for clinical practice.

Risk factors for inadequate bowel preparation before colonoscopy: a retrospective cohort study

BACKGROUND

Colonoscopy is the standard and most effective screening tool for colonic diseases and the accuracy of colonoscopy depends on the quality of bowel preparation. The aim of this study was to analyze the risk factors for inadequate bowel preparation before colonoscopy.

METHODS

In this retrospective study, patients who underwent colonoscopy in 2018 and received 3 L of Polyethylene Glycol Electrolytes powder were included. They were instructed to drink 1.5 L the night before the colonoscopy and 1.5 L 4-6 h before the procedure given in doses of 250 ml every 10 min with 30 ml of simethicone given 4-6 h before the colonoscopy. Patient- and procedure-related parameters were recorded. An adequate bowel preparation was defined as all 3 segments rated 2 or 3 on the Boston Bowel Preparation scale. Risk factors for inadequate bowel preparation were identified using multivariate logistic regression analysis.

RESULTS

A total of 6720 patients were included in the present study. The mean age of these patients was 49.7 ± 13.0 years old. Inadequate bowel preparation was found in 233 (12.4%), 139 (6.4%), 131 (7%), 68 (8.6%) patients in spring, summer, autumn and winter respectively. On the multivariate analysis, male gender (OR: 1.295; 95% CI: 1.088-1.542; P = 0.005), inpatient status (OR: 1.377; 95% CI: 1.040-1.822; P = 0.025) and season (spring vs. winter, OR: 1.514; 95% CI: 1.139-2.012; P = 0.004) were the independent risk factors for inadequate bowel preparation.

CONCLUSIONS

Male gender, inpatient status and spring season were the independent risk factors for inadequate bowel preparation. For patients with risk factors for inadequate bowel preparation, enhanced bowel preparation and instructions may help to optimize the quality of bowel preparation.

A novel ultra-low-volume regimen combining 1 L polyethylene glycol and linaclotide versus 2 L polyethylene glycol for colonoscopy cleansing in low-risk individuals: a randomized controlled trial

BACKGROUND AND AIMS

The single dose of 2 L polyethylene glycol (PEG) has shown high cleaning efficacy and tolerability in low-risk patients. However, the dosage of this regimen is still challenging for many patients. We investigated the efficacy and tolerability of a novel ultra-low-volume regimen using 1 L PEG and linaclotide (1 L PEG+L) versus a single dose of 2 L PEG in low-risk patients.

METHODS

In this prospective, randomized, observer-blinded, multicenter study, low-risk adult patients scheduled for colonoscopy were enrolled and randomized (1:1) to receive the 1 L PEG+L regimen or the 2 L PEG regimen. The primary outcome was the effectiveness of bowel cleansing according to the Boston Bowel Preparation Scale. Secondary outcomes included cecal intubation rate, cecal insertion time, withdrawal time, polyp detection rate and adenoma detection rate, tolerability, adverse events, and willingness to repeat bowel preparation. The full analysis set (FAS) and per-protocol set (PPS) were used for statistical analyses.

RESULTS

A total of 548 patients comprised the FAS, and 522 patients comprised the PPS. Noninferiority on adequate bowel cleansing of 1 L PEG+L vs 2 L PEG was established both in FAS (90.5% vs 91.6%, P = .644) and PPS (90.3% vs 92.4%, P = .390). There were no significant differences regarding the total score and each segment scores of the Boston Bowel Preparation Scale, cecal intubation rate, cecal insertion time, withdrawal time, polyp detection rate, and adenoma detection rate (all, P > .05). However, patients in the 1 L PEG+L group reported less nausea (7.7% vs 17.1%, P < .01) and vomiting (4.0% vs 10.9%, P < .01) and had a higher willingness to repeat bowel preparation (95.2% vs 82.2%, P < .01).

CONCLUSIONS

The regimen of 1 L PEG+L was not inferior to 2 L PEG on colon cleansing, with better tolerability and higher willingness to repeat the bowel preparation in a low-risk population. (Clinical trial registration number: ChiCTR2100053273.).

Endoscopic surveillance after surgery for colorectal cancer

Colorectal cancer (CRC) is one of the most common cancers worldwide and its global incidence is rapidly increasing among adults younger than 50 years, especially in the 20-39 age group. Once a curative resection is achieved, surveillance is mandatory. Colonoscopy has a pivotal role aimed at resecting premalignant neoplasms and detecting cancer at a curable stage. In the current review, an update on the role of surveillance colonoscopy after CRC is provided, considered the most recent international guidelines and evidence published on this issue. In particular, several questions have been answered, why, how and how often colonoscopy should be performed, whether intensive surveillance is more effective than standard surveillance, how endoscopically resected T1 cancer should be followed, the different management existing between colon and rectal cancer, and, finally, how to improve the endoscopic surveillance. In a period of resource constraints, appropriateness will be mandatory, thus understanding how to optimize the role of colonoscopy in the surveillance of patients with a history of CRC is of crucial importance. Improving the quality of colonoscopy and identifying risk factors for recurrent and new-onset CRC, will allow us to individualize the surveillance program while sparing health care cost.

Factors affecting the quality of bowel preparation for colonoscopy in hard-to-prepare patients: Evidence from the literature

Adequate bowel cleansing is critical for a high-quality colonoscopy because it affects diagnostic accuracy and adenoma detection. Nevertheless, almost a quarter of procedures are still carried out with suboptimal preparation, resulting in longer procedure times, higher risk of complications, and higher likelihood of missing lesions. Current guidelines recommend high-volume or low-volume polyethylene glycol (PEG)/non-PEG-based split-dose regimens. In patients who have had insufficient bowel cleansing, the colonoscopy should be repeated the same day or the next day with additional bowel cleansing as a salvage option. A strategy that includes a prolonged low-fiber diet, a split preparation regimen, and a colonoscopy within 5 h of the end of preparation may increase cleansing success rates in the elderly. Furthermore, even though no specific product is specifically recommended in the other cases for difficult-to-prepare patients, clinical evidence suggests that 1-L PEG plus ascorbic acid preparation are associated with higher cleansing success in hospitalized and inflammatory bowel disease patients. Patients with severe renal insufficiency (creatinine clearance < 30 mL/min) should be prepared with isotonic high volume PEG solutions. Few data on cirrhotic patients are currently available, and no trials have been conducted in this population. An accurate characterization of procedural and patient variables may lead to a more personalized approach to bowel preparation, especially in patients undergoing resection of left colon lesions, where intestinal preparation has a poor outcome. The purpose of this review was to summarize the evidence on the risk factors influencing the quality of bowel cleansing in difficult-to-prepare patients, as well as strategies to improve colonoscopy preparation in these patients.

Advanced intestinal regulation improves bowel preparation quality in patients with constipation: A systematic review and network meta-analysis

Background: Inadequate bowel preparation (IBP) has a critical influence on the colonoscopy procedure and is associated with significantly lower rates of detection of colorectal lesions. Constipation is an important risk factor of IBP, and some studies have attempted to address the bowel cleansing for constipated patients. However, there is still lack of consensus to guide the clinical work of bowel preparation (BP) for patients with constipation. Therefore, we aimed to perform a network meta-analysis to compare the overall efficacy of various regimens for BP in constipated patients. Methods: We performed a comprehensive search of PubMed, MEDLINE, EMBASE, Cochrane, and Web of science to identify randomized controlled trials (RCTs) of bowel preparation regimens in constipated patients, update to January 2021. Two investigators independently evaluated articles and extracted data. The odds ratio (OR) with a 95% confidence interval (CI) was used to combine dichotomous data of the primary outcome which was defined as adequate bowel preparation (ABP). Rank probability was used to exhibit the outcome of the network meta-analysis. Results: Eleven studies that included 1891 constipated patients were identified as suitable for inclusion. The proportion of ABP was associated with the administration of intensive regimen (OR 2.19, 95% CI 1.16-4.17, p = .02, I2 = 84%). Moreover, an intensive regimen had a significant efficacy and light heterogeneity when the same basic laxative program was used (OR 4.06, 95% CI 3.04-5.43, p < .0001, I2 = 0%). In the network meta-analysis, the protocol of a normal regimen + A (normal regimen plus advanced intestinal regulation) had a significant effect for bowel preparation compared with a normal regimen + IR (normal regimen plus irritating laxative regimen) (OR 5.21, 95% CI 1.18-24.55), H PEG (4L- polyethylene glycol) (OR 8.70, 95% CI 1.75-52.56), and normal regimen (NR) (OR 7.37, 95% CI 2.33-26.39). In the remaining protocols, no significant difference was observed in any comparison. No significant severe adverse events (AEs) associated with bowel preparation were reported in included studies. Conclusion: Intensive regimens could improve bowel cleansing quality for patients with constipation, and advanced intestinal regulation regimens may be superior to others.

Application of a multispecies probiotic reduces gastro-intestinal discomfort and induces microbial changes after colonoscopy

Even after decades of research and pharmaceutical development, cancer is still one of the most common causes of death in the western population and the management of cancer will remain a major challenge of medical research. One of the most common types of cancer is colorectal cancer (CRC). Prevention by detection of early-stage precursors is the most reliable method to prevent CRC development. In dependence of age, familial predisposition, and other risk factors the preventative routine screening for CRC by colonoscopy should be performed at least twice in intervals of about ten years. Although colonoscopy is a life-saving clinical examination reducing both incidence and mortality of CRC significantly, it has still a bad reputation in the population as an uncomfortable procedure with unpleasant side effects lasting sometimes over days to weeks. These effects are most likely caused by the bowel preparation before colonoscopy, which is crucial for a successful colonoscopy with high quality. Beside pain, bleeding and other rare but severe complications of colonoscopy, cleaning of the intestinal mucosa alters the gut microbiome significantly and consistently. Abdominal pain, cramps, diarrhea, nausea, bloating, and constipation are common adverse events which can continue to affect patients for days or even weeks after the procedure. In this multicenter, placebo controlled, double blind clinical trial, we investigated the effect of an intervention with a multispecies probiotic formulation for 30 days on the adverse events due to bowel preparation. We show that the treatment of participants with the multispecies probiotic formulation decreases the number of days with constipation significantly, and reduced pain, bloating, diarrhea, and general discomfort. 16S based amplicon analyses reveal recovery of administered probiotic strains from stool samples and differences in alpha diversity dynamics with higher variability in the probiotic group compared to the placebo group. In conclusion, the probiotic ameliorates the side effects after colonoscopy and might be an important supplement to increase acceptance of this life-saving preventative examination. Further, we present here for the first time that probiotic intervention of only 30 days affects alpha diversity parameters in stool samples.

Impact of glucagon-like peptide 1 receptor agonist liraglutide and dipeptidyl peptidase-4 inhibitor sitagliptin on bowel cleaning and gastrointestinal symptoms in type 2 diabetes

Objective: Glucagon-like peptide 1 receptor agonists (GLP-1 RAs) and dipeptidyl peptidase-4 inhibitors (DPP-4i) profoundly affect the gastrointestinal motor system, which may increase the incidence of inadequate bowel cleaning and gastrointestinal symptoms. Hence, this observational study mainly aimed to assess the influence of GLP-1 RAs liraglutide and DPP-4i sitagliptin on bowel preparation in type 2 diabetes (T2DM). Method: This observational study consecutively enrolled T2DM scheduled for a colonoscopy. Participants were prospectively separated into the liraglutide group (n = 120), sitagliptin group (n = 120), and control group (n = 120) based on the current hypoglycemic regimen. 3L split-dose polyethylene glycol regimens were used for bowel preparation. Experienced gastrointestinal endoscopists conducted colonoscopies. Lawrance Bowel-Preparation Tolerability Questionnaire and Boston Bowel Preparation Scale (BBPS) were conducted to assess bowel cleaning quality, tolerability, and safety. Results: The incidence of inadequate bowel cleaning was 17.5% in the liraglutide group, 20.5% in the sitagliptin group, and 21.7% in the control group. The difference among the three groups was not statistically significant (p = 0.927). Meanwhile, there were no significant differences in the mean BBPS, cecal intubation time, and polyp-detecting rates among the three groups (all p > 0.0.05). Nausea, vomiting, and bloating scores were increased in the liraglutide group compared with the other two groups (p < 0.05), whereas most were mild or very mild. Subgroup analyses showed that the incidence of inadequate bowel cleaning in T2DM with diabetic peripheral neuropathy (DPN) was increased in the liraglutide group compared with the sitagliptin group (61.3% vs. 32.1%, p = 0.022) and control group (61.3% vs. 32.8%, p = 0.025). Conclusion: GLP-1RA liraglutide or DPP-4i sitagliptin did not significantly increase the incidence of inadequate bowel cleaning and gastrointestinal symptoms during bowel preparation. Liraglutide may increase the incidence of inadequate bowel preparation in patients with DPN. This study reveal that more attention and aggressive bowel preparation regimens should be given to the T2DM with DPN. Clinical Trial Registration: (https://www.chictr.org.cn/index.aspx), identifier (ChiCTR2200056148).

Superiority of a preparation-related model for predicting inadequate bowel preparation in patients undergoing colonoscopy: A multicenter prospective study

BACKGROUND AND AIM

Three models based on patient-related factors have been developed to predict inadequate bowel preparation (BP). However, the performance of the models seems suboptimal. This study aimed to develop a novel preparation-related model and compare it with the available patient-related models.

METHODS

Patients receiving standard BP were prospectively enrolled from five endoscopic centers. Patient-related and preparation-related factors for inadequate BP (defined by segmental Boston Bowel Preparation Scale score < 2) were identified by logistic regression. A preparation-related model was derived and internally validated in 906 patients. The comparisons of models were assessed by discrimination and calibration. The preparation-related model was also externally validated.

RESULTS

Several patient-related factors (male and American Society of Anesthesiologists Physical Status Classification System score ≥ 3) and preparation-related factors (drinking-to-stool interval ≥ 3 h, preparation-to-colonoscopy interval ≥ 6 h, and poor rectal effluent) were found to be independently associated with inadequate BP (all P < 0.05). C-statistics was 0.81 for the preparation-related model in the training cohort (n = 604), significantly higher than three available patient-based models (0.58-0.61). Similar results were observed in the validation cohort (n = 302). Calibration curves showed close agreement in the preparation-related model (R²  = 0.315 in the training cohort and 0.279 in the validation cohort). The preparation-related model was externally validated in another 606 patients with C-index of 0.80.

CONCLUSIONS

A new preparation-related model (consisting of drinking-to-stool interval ≥ 3 h, preparation-to-colonoscopy interval ≥ 6 h, and poor last rectal effluent) was developed and performed better than three available patient-related models. This easy-to-use model may be a useful decision-support tool on individualized plans in patients undergoing BP.

Determinants of symptom burden related to bowel preparation for colonoscopy

BACKGROUND

Symptoms developing during bowel preparation are major concerns among subjects who refuse the procedure.

AIMS

We aimed to explore the determinants of symptoms occurring during preparation among patients undergoing elective colonoscopy.

METHODS

This is a prospective multicenter study conducted in 10 Italian hospitals. A multidimensional approach collecting socio-demographic, clinical, psychological and occupational information before colonoscopy through validated instruments was used. Outcome was a four-category cumulative score based on symptoms occurring during preparation, according to the Mayo Clinic Bowel Prep Tolerability Questionnaire, weighted by intensity. Missing values were addressed through multiple imputation. Odds ratios (OR) and 95% confidence intervals (CI) were estimated through multivariate logistic regression models.

RESULTS

1137 subjects were enrolled. Severe symptoms were associated with female sex (OR=3.64, 95%CI 1.94-6.83), heavier working hours (OR=1.13, 95% CI=1.01-1.25), previous gastrointestinal symptoms (OR=7.81, 95% CI 2.36-25.8 for high score), somatic symptoms (OR=2.19, 95% CI=1.06-4.49 for multiple symptoms), day-before regimen (OR=2.71, 95%CI 1.28-5.73). On the other hand, age ≥60 years (OR=0.10, 95% CI 0.02-0.44) and good mood (p=0.042) were protective factors. A high-risk profile was identified, including women with low mood and somatic symptoms (OR=15.5, 95%CI 4.56-52.7).

CONCLUSIONS

We identified previously unreported determinants of symptoms burdening bowel preparation and identified a particularly vulnerable phenotype. Symptoms during preparation especially impact heavier working activity.

Comparison of 2 L Polyethylene Glycol Plus Ascorbic Acid and 4 L Polyethylene Glycol in Elderly Patients Aged 60-79: A Prospective Randomized Study

BACKGROUND

The bowel-cleansing efficacy and safety of 2 L polyethylene glycol (PEG) with ascorbic acid (2L PEG + Asc) has rarely been studied in the elderly population. In this randomized trial, we compared the bowel cleanliness, safety, and tolerability of 2L PEG + Asc with those of 4 L PEG in an elderly population aged 60-79.

METHODS

Study participants were randomized either to 2L PEG + Asc or 4L PEG. The primary endpoint was the success rate of bowel preparation, using the Boston Bowel Preparation Scale. Before colonoscopy, all participants were questioned about adverse events and tolerability regarding purgative ingestion.

RESULTS

A total of 347 individuals were enrolled (2L PEG + Asc, 174; 4L PEG, 173). Mean age in the 2L PEG + Asc and the 4L PEG was 69.3 ± 5.6 and 69.3 ± 5.0, respectively (P = 0.917). The rate for successful bowel cleansing was comparable between the 2L PEG + Asc (92%) and the 4L PEG (96%, P = 0.118). Total ingested liquid including purgative and water was lower in the 2L PEG + Asc group (2.9 L) than in the 4L PEG group (4.2 L, P < 0.001). The tolerability of purgative was superior in the 2L PEG + Asc (overall satisfaction, P < 0.001; willingness to reuse, P < 0.001). There were no serious adverse events during the trial.

CONCLUSIONS

The bowel-cleansing efficacy of 2L PEG + Asc was comparable to that of 4L PEG. Tolerability was superior in the 2L PEG + Asc group. For older people, 2L PEG + Asc is an efficacious and safe bowel cleanser. (Clinical trial registration number: KCT0004123).

Endoscopic Disease Activity and Biologic Therapy Are Independent Predictors of Suboptimal Bowel Preparation in Patients with Inflammatory Bowel Disease Undergoing Colonoscopy

BACKGROUND AND AIMS

Optimal bowel preparation (BP) is critical for endoscopic assessment of inflammation and dysplasia in patients with inflammatory bowel disease (IBD). Comorbidities and patient-related factors have been associated with suboptimal BP (SOBP) in the general population. We sought to identify disease-specific characteristics that may impact the quality of BP in patients with IBD.

METHODS

We conducted a retrospective analysis of adult IBD patients who underwent outpatient colonoscopies between January 2014 and September 2020 at a large academic medical center. Quality of BP was documented using the Boston Bowel Preparation Scale (BBPS) or the Aronchick scale and dichotomized into "suboptimal" (BBPS 0-5 or Aronchick "fair," "poor," unsatisfactory") and "optimal" (BBPS 6-9 or Aronchick "excellent," "good"). IBD-specific and other factors associated with SOBP were evaluated using logistic regression analyses.

RESULTS

Among a total of 395 IBD patients [54% males, mean age 40 years, 63% with Crohn's disease (CD), 35% with ulcerative colitis (UC)], 24.8% had SOBP. On multivariable analysis, moderate-to-severe endoscopic disease vs mild or inactive disease was associated with a higher odds of SOBP [adjusted OR 2.7(95% CI 1.52-4.94)], whereas baseline biologic use was associated with a lower odds of SOBP [aOR 0.24(0.09-0.65)] among the overall IBD cohort. Additionally, age > 65 years [aOR 2.99(1.19-7.54)] and single-dose vs split-dose BP [aOR 2.37(1.43-3.95)] were predictors of SOBP. In the subgroup analysis by IBD type, moderate-to-severe endoscopic disease predicted SOBP among both CD and UC cohorts.

CONCLUSION

Endoscopic disease activity was predictive of SOBP, and biologic therapy was protective against SOBP among IBD patients.

External validation of two prediction models for adequate bowel preparation in Asia: a prospective study

BACKGROUND

Several models for predicting adequate bowel preparation are available but have never been externally validated. The aim of this study is to compare the available models in an independent population.

METHODS

This study prospectively recruited 500 consecutive patients from August to December 2020 from the Endoscopy Center of a tertiary hospital. All patients underwent the same bowel preparation regimen. The discrimination of the prediction models was quantified with the area under the receiver operating characteristic curve (AUC), and the 95% confidence interval (CI) was calculated for each AUC.

RESULTS

Finally, 461 patients were eligible for this study. A total of 110 (23.9%) patients were deemed to show inadequate bowel preparation during colonoscopy. There were significant differences between patients with and without adequate bowel preparation in terms of current hospitalization, procedure time, comorbidities (including diabetes and constipation), American Society of Anesthesiologists Physical Status Classification System score (ASA) ≥ 3, medication usage, and abdominal/pelvic surgery. The prediction models performed as follows: the Dik ≥ 2 model, the Dik ≥ 3 model, and the Antonio > 1.225 model had AUCs of 0.660 (95% CI = 0.604-0.717), 0.691 (95% CI = 0.646-0.733), and 0.645 (95% CI = 0.615-0.704), respectively. Comparison of the two prediction models showed no significant improvement (Antonio > 1.225 vs. Dik ≥ 3, 1.801, 95% CI =  -0.004-0.096, P = 0.072).

CONCLUSIONS

Both models are potentially helpful. However, it is necessary to develop or improve a prediction model to obtain a more suitable and detailed model.

TRIAL REGISTRATION

ClinicalTrials.gov, Number NCT04607161.

The Effectiveness and Tolerability of a Very Low-Volume Bowel Preparation for Colonoscopy Compared to Low and High-Volume Polyethylene Glycol-Solutions in the Real-Life Setting

Adequate bowel cleansing is essential for high-quality colonoscopy. Recently, a new very low-volume 1 litre (1L) polyethylene glycol (PEG) plus ascorbate solution (ASC) has been introduced. Our aims were to assess the effectiveness and tolerability of this product compared to low-volume 2L PEG-ASC and high-volume 4L PEG solutions, in a real-life setting. In six endoscopy units in Sweden, outpatients undergoing colonoscopy were either prescribed solutions according to local routines, or the very low-volume solution in split dose regimen. Bowel cleansing effectiveness and patient experience was assessed using the Boston Bowel preparation scale (BBPS) and a patient questionnaire. A total of 1098 patients (mean age 58 years, 52% women) were included. All subsegment and the total BBPS scores were significantly greater for 1L PEG-ASC in comparison to other solutions (p < 0.05 for 1L PEG-ASC and 4L PEG for transverse and left colon, otherwise p < 0.001). Nausea was more frequent with 1L PEG-ASC compared to 2L PEG-ASC (p < 0.001) and vomiting were more often reported compared to both other solutions (p < 0.01 and p < 0.05 for 2L PEG-ASC and 4L PEG, respectively). Smell, taste, and total experience was better for 1L PEG-ASC compared to 4L PEG (p < 0.001), and similar compared to the 2L PEG-ASC. In conclusion, 1L PEG-ASC leads to better bowel cleansing compared to 2L PEG-ASC or 4L PEG products, with similar or greater patient satisfaction.

Rectal Evacuation Disorders are Associated With Poor Bowel Preparation in Patients With Chronic Constipation: Results From Two Centers

INTRODUCTION

We evaluated factors that can predict the adequacy of bowel preparation in patients with chronic constipation undergoing colonoscopy.

MATERIALS AND METHODS

We identified patients with chronic constipation who underwent anorectal manometry and at least 1 colonoscopy at 2 tertiary referral centers from 2003 to 2019. We also identified a subgroup of patients who underwent colonic transit testing through radiopaque marker testing. We determined demographic, medical, and constipation-related factors associated with poor bowel preparation and their effect on standardized quality metrics using univariate and multivariate analyses.

RESULTS

We identified 274 patients with chronic constipation who underwent anorectal manometry testing. Both outlet dysfunction (prolonged balloon expulsion) and slow-transit constipation were associated with suboptimal bowel preparation. Outlet dysfunction was also associated with decreased cecal intubation rates, adenoma detection rates, and sessile serrated polyp detection rates. In multivariable analyses controlling for demographics and known factors associated with poor bowel preparation, outlet dysfunction was associated with an almost 3-fold odds of suboptimal bowel preparation [odds ratio (OR): 2.9; 95% confidence interval (CI): 1.6-5.1] and a 3-fold reduction in cecal intubation rates (OR: 0.3; 95% CI: 0.1-0.8). Among those with radiopaque marker colonic transit testing available, slow-transit constipation was associated with a >2-fold odds of suboptimal bowel preparation (OR: 2.2; 95% CI: 1.1-4.4).

CONCLUSIONS

Among a cohort of patients with chronic constipation undergoing colonoscopy, outlet dysfunction was associated with suboptimal bowel preparation and other quality metrics. Constipated patients with a rectal evacuation disorder may represent a subgroup of patients that could benefit from individualized strategies for better bowel preparation.

Effect of the Weekend on Bowel Preparation Quality in Outpatient Colonoscopies

INTRODUCTION

Inadequate bowel preparation has been associated with a higher likelihood of missing adenomatous polyps. Colonoscopies immediately following a weekend may be prone to inadequate bowel preparation. This study aims to evaluate if day of the week is a predictor of bowel preparation adequacy, while assessing other patient and procedural variables and their effect on the Boston Bowel Preparation Scale (BBPS).

METHODS

A retrospective review was conducted of all adult patients undergoing outpatient colonoscopy between January 2015 and April 2020. Adequacy of bowel preparation was compared among all days of the week and days following federal holidays. Secondary outcomes included patient demographics, indication and timing of the procedure.

RESULTS

Of 4,279 colonoscopies, Monday had the highest rate of inadequate preparation (BBPS < 6) (16.5%) compared to other days of the week (p < .001). Post-holiday procedures were not associated with poor bowel preparation (p = .901). Similarly, on multivariate analysis, we found that procedures on Monday (OR 1.67 95%CI 1.33-2.10, p < .001) and African-American race (OR 1.34 95%CI 1.11-1.62, p = .003) were associated with inadequate bowel preparation. Females were more likely to have adequate bowel preparation (OR 0.71 95%CI 0.59-0.86, p < .001).

DISCUSSION

Bowel preparation on Mondays is more likely to be inadequate than other days of the week. Additionally, gender and ethnicity appear to be associated with quality of bowel preparation. A better characterization of procedural and patient variables can lead to a more personalized approach to bowel preparation.

Predictors of poor bowel preparations and colonoscopy cancellations in inpatient colonoscopies, a single center retrospective study

BACKGROUND

An adequate bowel preparation prior to colonoscopy is a major quality-limiting factor that determines both the diagnostic and therapeutic yield of a colonoscopy. Colonoscopy is considered the gold standard for colon cancer screening and it is the primary approach to the workup of hematochezia, diarrhea and iron deficiency anemia (IDA). Several modifiable factors of bowel prep adequacy have been identified, that account for around 25% of inadequate bowel preparations in outpatient colonoscopies. However, the literature is sparse when examining the factors associated with inadequate preparations and procedure cancellations in an inpatient hospital setting. We aim to identify factors that affect bowel preparation adequacy and procedure cancellations among diagnostic colonoscopies performed during hospitalization.

METHODS

We retrospectively reviewed the electronic medical records of 1,500 consecutive patients who had a diagnostic colonoscopy as an inpatient at a tertiary level hospital over a 2-year period. All patients were administered a clear liquid diet the day prior to the colonoscopy. Patients were then instructed to drink 4 L of polyethylene glycol (PEG, Golytely) between 5 am to 9 am on the day of the procedure. The clinical course of each case was followed to identify quality of preparations, cancelled procedures and the reasons for cancellations. We applied univariate and multivariate logistic regression analysis to identify variables to predict cancellation and poor preparation.

RESULTS

A total of 1,029 patients were included in the study. 194 (18.8%) patients had colonoscopy cancellations and 268 (26.0%) had poor bowel preparations. Multivariate analysis revealed these factors to be associated with colonoscopy cancellations: education at the graduate school level [odds ratio (OR) =1.93, P=0.04], Hispanic ethnicity (OR =0.47, P<0.01), hemoglobin level <10 g/dL (OR =1.41, P=0.05) and if the colonoscopy was done for other indications (OR =0.53, P=0.04). Factors associated with poor bowel preparation on multivariate analysis, were dementia (OR =2.44, P=0.02), gastroparesis (OR =3.97, P=0.01) and inpatient opioids use (OR =1.69, P=0.04).

CONCLUSIONS

The rate of colonoscopy cancellations and poor bowel preparations in inpatient colonoscopies were high, and we were able to identify predictors of inadequate colon preparation and procedure cancellations. Exploring more individualized colon preparation regimens based on personal risk factors could reduce the number of inadequate and cancelled colonoscopies in an inpatient setting.

Odds of Incomplete Colonoscopy in Colorectal Cancer Screening Based on Socioeconomic Status

The aim of this study is to investigate the association between socioeconomic status (SES) and the risk of having an incomplete colonoscopy (IC) in the Danish Colorectal Cancer (CRC) Screening Program. In this register-based study we included 71,973 participants who underwent colonoscopy after a positive fecal immunochemical test in the Danish CRC Screening Program. The main exposure, SES, was defined by income and education, and the outcome by complete or incomplete colonoscopy. Among the participants, 5428 (7.5%) had an incomplete colonoscopy. The odds ratio (OR) for ICs due to inadequate bowel preparation was 1.67 (95% CI: 1.46; 1.91) for income in the 1 quartile compared to income in the 4th quartile. ORs for income in the 2nd quartile was 1.38 (95% CI: 1.21; 1.56) and 1.17 (95% CI: 1.03; 1.33) for income in the 3rd quartile. For the educational level, an association was seen for high school/vocational education with an OR of 0.87 (95% CI: 0.79; 0.97) compared to higher education. For ICs due to other reasons, the level of income was associated with the risk of having an IC with an OR of 1.19 (95% CI: 1.05; 1.35) in the 1st quartile and an OR of 1.19 (95% CI: 1.06; 1.34) in the 2nd quartile. For the educational level, there were no significant associations. Low income is associated with high risk of having an IC, whereas educational level does not show the same unambiguous association.

Efficacy of ultra-low volume (≤1 L) bowel preparation fluids: Systematic review and meta-analysis

BACKGROUND AND AIMS

High-quality bowel preparation is paramount for the diagnostic accuracy and safety of colonoscopy; however, it is often difficult for patients to adhere to high-volume laxatives, which may contribute to poor bowel preparation. This review aims to assess the efficacy of bowel preparation fluids of 1 L or less (≤1 L).

METHODS

We performed a systematic review including all relevant randomized controlled trials on ultra-low volume (≤1 L) bowel preparation fluids for colonoscopy published since 2015. Primary endpoint was the percentage of adequately prepared patients. Secondary endpoints included adenoma detection rate (ADR) and safety.

RESULTS

Bowel preparation with sodium picosulfate/magnesium citrate (SPMC; 19 trials, n = 10,287), 1L-polyethylene glycol with ascorbate (PEGA; 10 trials, n = 1717), sodium phosphate (NaP; 2 trials, n = 621), and oral sulfate solution (OSS; 3 trials, n = 597) was adequate in 75.2%, 82.9%, 81.9%, and 92.1%, respectively, of patients; however, heterogeneity between studies was considerable (I² range: 86-98%). Pooled ADRs were 31.1% with SPMC, 32.3% with 1L-PEGA, 30.4% with NaP, and 40.9% with OSS. Temporary electrolyte changes were seen with all ultra-low volume bowel preparation fluid solutions but without sustained effects in most patients.

CONCLUSION

Ultra-low volume bowel preparation fluids do not always meet the 90% quality standard for adequate bowel preparation as defined by current guidelines. Nonetheless, they may be considered in patients intolerant for higher-volume laxatives and without risk factors for inadequate bowel preparation or dehydration-related complications.

Validation and Application of Predictive Models for Inadequate Bowel Preparation in Colonoscopies in a Tertiary Hospital Population

Background: Bowel preparation is a major quality criterion for colonoscopies. Models developed to identify patients with inadequate preparation have not been validated in external cohorts. We aim to validate these models and determine their applicability. Methods: Colonoscopies between April and November 2019 were retrospectively included. Boston Bowel Preparation Scale ≥2 per segment was considered adequate. Insufficient data, incomplete colonoscopies, and total colectomies were excluded. Two models were tested: model 1 (tricyclic antidepressants, opioids, diabetes, constipation, abdominal surgery, previous inadequate preparation, inpatient status, and American Society of Anesthesiology [ASA] score ≥3); model 2 (co-morbidities, tricyclic antidepressants, constipation, and abdominal surgery). Results: We included 514 patients (63% males; age 61.7 ± 15.6 years), 441 with adequate preparation. The main indications were inflammatory bowel disease (26.1%) and endoscopic treatment (24.9%). Previous surgery (36.2%) and ASA score ≥3 (23.7%) were the most common comorbidities. An ASA score ≥3 was the only identified predictor for inadequate preparation in this study (p < 0.001, OR 3.28). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of model 1 were 60.3, 64.2, 21.8, and 90.7%, respectively. Model 2 had a sensitivity, specificity, PPV, and NPV of 57.5, 67.4, 22.6, and 90.5%, respectively. The AUC for the ROC curves was 0.62 for model 1, 0.62 for model 2, and 0.65 for the ASA score. Conclusions: Although both models accurately predict adequate bowel preparation, they are still unreliable in predicting inadequate preparation and, as such, new models, or further optimization of current ones, are needed. Utilizing the ASA score might be an appropriate approximation of the risk for inadequate bowel preparation in tertiary hospital populations.

Efficacy and tolerability of high and low-volume bowel preparation compared: A real-life single-blinded large-population study

BACKGROUND

Low-volume preparations for colonoscopy have shown similar efficacy compared to high-volume ones in randomized controlled trials (RCT). However, most RCTs do not provide data about clinical outcomes including lesions detection rate. Moreover, real-life comparisons are lacking.

AIM

To compare efficacy (both in terms of adequate bowel preparation and detection of colorectal lesions) and tolerability of a high-volume (HV: 4 L polyethylene glycol, PEG) and a low-volume (LV: 2 L PEG plus bisacodyl) bowel preparation in a real-life setting.

METHODS

Consecutive outpatients referred for colonoscopy were prospectively enrolled between 1 December 2014 and 31 December 2016. Patients could choose either LV or HV preparation, with a day-before schedule for morning colonoscopies and a split-dose for afternoon procedures. Adequate bowel preparation according to Boston Bowel Preparation Scale (BBPS), clinical outcomes including polyp detection rate (PDR), adenoma detection rate (ADR), advanced adenoma detection rate (AADR), sessile/serrated lesion detection rate (SDR) and cancer detection rate and self-reported tolerability of HV and LV were blindly assessed.

RESULTS

Total 2040 patients were enrolled and 1815 (mean age 60.6 years, 50.2% men) finally included. LV was chosen by 52% of patients (50.8% of men, 54.9% of women). Split-dose schedule was more common with HV (44.7% vs 38.2%, P = 0.005). High-definition scopes were used in 33.4% of patients, without difference in the two groups (P = 0.605). HV and LV preparations showed similar adequate bowel preparation rates (89.2% vs 86.6%, P = 0.098), also considering the two different schedules (HV split-dose 93.8% vs LV split-dose 93.6%, P = 1; HV day-before 85.5% vs LV day-before 82.3%, P = 0.182). Mean global BBPS score was higher for HV preparations (7.1 ± 1.7 vs 6.8 ± 1.6, P < 0.001). After adjustment for sex, age and indications for colonoscopy, HV preparation resulted higher in PDR [Odds ratio (OR) 1.32, 95%CI: 1.07-1.63, P = 0.011] and ADR (OR 1.29, 95%CI 1.02–1.63, P = 0.038) and comparable to LV in AADR (OR 1.51, 95%CI 0.97-2.35, P = 0.069), SDR and cancer detection rate. The use of standard-definition colonoscopes was associated to lower PDR (adjusted OR 1.59, 95%CI: 1.22-2.08, P < 0.001), ADR (adjusted OR 1.71, 95%CI: 1.26–2.30, P < 0.001) and AADR (adjusted OR 1.97, 95%CI: 1.09-3.56, P = 0.025) in patients receiving LV preparation. Mean Visual Analogue Scale tolerability scored equally (7, P = 0.627) but a ≥ 75% dose intake was more frequent with LV (94.6% vs 92.1%, P = 0.003).

CONCLUSION

In a real-life setting, PEG-based low-volume preparation with bisacodyl showed similar efficacy and tolerability compared to standard HV preparation. However, with higher PDR and ADR, HV should still be considered as the reference standard for clinical trials and the preferred option in screening colonoscopy, especially when colonoscopy is performed with standard resolution imaging.

Comparing the Real-World Effectiveness of High- Versus Low-Volume Split Colonoscopy Preparations: An Experience Through the British Columbia Colon Cancer Screening Program

Background

The British Columbia Colon Screening Program (BCCSP) is a population-based colon cancer screening program. In December 2018, physicians in Vancouver, Canada agreed to switch from a low-volume split preparation to a high-volume polyethylene glycol preparation after a meta-analysis of studies suggested superiority of the higher volume preparation in achieving adequate bowel cleansing and improving adenoma detection rates.

Aims

To compare the quality of bowel preparation and neoplasia detection rates using a high-volume split preparation (HVSP) versus a low-volume split preparation (LVSP) in patients undergoing colonoscopy in the BCCSP.

Methods

A retrospective review of patients undergoing colonoscopy through the BCCSP at St. Paul’s Hospital from July 2017 to November 2018 and December 2018 to November 2019 was conducted. Inclusion criteria included age 50 to 74 and patients undergoing colonoscopy through the BCCSP. Variables collected included patient demographics and bowel preparation quality. Rates of bowel preparation and neoplasia detection were analyzed using chi-squared test.

Results

A total of 1453 colonoscopies were included, 877 in the LVSP group and 576 in the HVSP group. No statistically significant difference was noted between rates of inadequate bowel preparation (LVSP 3.6% versus HVSP 2.8%; P = 0.364). Greater rates of excellent (48.4% versus 40.1%; P = 0.002) and optimal (90.1% versus 86.5%; P = 0.041) bowel preparation were achieved with HVSP. The overall adenoma detection rate was similar between the two groups (LVSP 53.1% versus HVSP 54.0%; P = 0.074). LVSP demonstrated higher overall sessile serrated lesion detection rate (9.5% versus 5.6%; P = 0.007).

Conclusions

Compared to LVSP, HVSP was associated with an increase in excellent and optimal bowel preparations, but without an improvement in overall neoplasia detection.

Volume of fluid consumption during preparation for colonoscopy is possibly the single most important determinant of bowel preparation adequacy

Background

The effectiveness and safety of colonoscopy are directly dependent on the quality of bowel preparation. Multiple risk factors for inadequate bowel preparation (IBP) have been identified; however, IBP is still reported in 20-30% of cases in most studies. We aimed to identify modifiable predictors of the adequacy of bowel preparation using sodium picosulfate, and to recommend easily modifiable parameters to increase the success rate of colonoscopies.

Methods

This was a single-center observational study of adult outpatients referred for an elective colonoscopy. Patients were interviewed prior to colonoscopy; volume of liquids consumed was calculated as number of 200-mL cups showed to the patient. Additional information, including medical history, diagnoses and regular medications, was procured from patients’ medical records. Univariate and multivariate regression analyses were performed to identify factors significantly associated with IBP in a subgroup analysis of high-risk patients.

Results

The rate of IBP in 1172 subjects was 19.4%. This rate decreased as fluid consumption increased, with a further drop associated with shorter intervals from end of preparation to colonoscopy. Drinking < 1.4 L significantly increased the risk of IBP (odds ratio [OR] 3.62, 95% confidence interval [CI] 2.65-4.95), while drinking ≥2 L was associated with adequate preparation (OR 0.09, 95%CI 0-0.42). These associations were stronger in high-risk individuals.

Conclusion

Greater fluid intake and short interval to colonoscopy are easily modifiable parameters that can substantially reduce the rate of IBP, especially among high-risk individuals.

Effects of a Personalized Smartphone App on Bowel Preparation Quality: Randomized Controlled Trial

Background

Adequate bowel preparation is essential for the visualization of the colonic mucosa during colonoscopy. However, the rate of inadequate bowel preparation is still high, ranging from 18% to 35%; this may lead to a higher risk of missing clinically relevant lesions, procedural difficulties, prolonged procedural time, an increased number of interval colorectal carcinomas, and additional health care costs.

Objective

The aims of this study are to compare bowel preparation instructions provided via a personalized smartphone app (Prepit, Ferring B V) with regular written instructions for bowel preparation to improve bowel preparation quality and to evaluate patient satisfaction with the bowel preparation procedure.

Methods

Eligible patients scheduled for an outpatient colonoscopy were randomized to a smartphone app group or a control group. Both the groups received identical face-to-face education from a research physician, including instructions about the colonoscopy procedure, diet restrictions, and laxative intake. In addition, the control group received written information, whereas the smartphone app group was instructed to use the smartphone app instead of the written information for the actual steps of the bowel preparation schedule. All patients used bisacodyl and sodium picosulfate with magnesium citrate as laxatives. The quality of bowel preparation was scored using the Boston Bowel Preparation Scale (BBPS) by blinded endoscopists. Patient satisfaction was measured using the Patient Satisfaction Questionnaire-18.

Results

A total of 87 patients were included in the smartphone app group and 86 in the control group. The mean total BBPS score was significantly higher in the smartphone app group (mean 8.3, SD 0.9) than in the control group (mean 7.9, SD 1.2; P=.03). The right colon showed a significantly higher bowel preparation score in the smartphone app group (mean 2.7, SD 0.5 vs mean 2.5, SD 0.6; P=.04). No significant differences were observed in segment scores for the mean transverse colon (mean 2.8, SD 0.4 vs mean 2.8, SD 0.4; P=.34) and left colon (mean 2.8, SD 0.4 vs mean 2.6, SD 0.5; P=.07). General patient satisfaction was high for the smartphone app group (mean 4.4, SD 0.7) but showed no significant difference when compared with the control group (mean 4.3, SD 0.8; P=.32).

Conclusions

Our personalized smartphone app significantly improved bowel preparation quality compared with regular written instructions for bowel preparation. In particular, in the right colon, the BBPS score improved, which is of clinical relevance because the right colon is considered more difficult to clean and the polyp detection rate in the right colon improves with improvement of bowel cleansing of the right colon. No further improvement in patient satisfaction was observed compared with patients receiving regular written instructions.

Trial Registration

ClinicalTrials.gov NCT03677050; https://clinicaltrials.gov/ct2/show/NCT03677050

The impact of language and ethnicity on preparation for endoscopy: A prospective audit of an East London Hospital Ward

RATIONALE, AIMS, AND OBJECTIVES

The efficacy, cost-effectiveness, and safety of a number of endoscopic procedures are largely dependent on optimal preparation. Despite this however, inadequate or suboptimal preparation is relatively common. Most studies have revealed inadequate preparation for between 20% and 30% of patients. This audit sought to examine the impact of English language proficiency, and ethnicity, on endoscopic preparation and procedure success or failure.

METHOD

A prospective audit was developed. Using convenience sampling, participants were consecutive patients recruited over a six-month period, who were aged 18 and over, attending an east London endoscopy ward for a routine (pre-booked) endoscopy procedure for which they had received preparation instructions to carry out at home.

RESULTS

Almost one-third of the sample had adequate or very poor English proficiency. When an interpreter was used it was overwhelmingly a member of the patients' family or a member of staff. There was no significant relationship between gender, age, ethnic group, English language proficiency, whether an interpreter was needed, the type of procedure carried out and inadequate preparation.

CONCLUSIONS

Amongst these patients, we found that a little more than 20% of participants were inadequately prepared for their endoscopic procedure. We found no relationship between language proficiency on preparation. Given the mixed literature on interventions to improve preparation before endoscopic procedures, further directions are identified to work toward the development and testing of a novel intervention amongst this population. In identifying those who may be at risk for inadequate preparation for endoscopic procedures, practice needs to take into account a range of factors beyond language and ethnicity. Furthermore, the persistent reliance on family members to interpret information sheets and preparation advice suggests that revision and/or development of culture and language-specific materials is necessary.

Bowel-cleansing efficacy of the 1L polyethylene glycol-based bowel preparation NER1006 (PLENVU) in patient subgroups in two phase III trials

BACKGROUND

Adequate bowel preparation prior to colonoscopy is essential for visualization of the colonic mucosa to maximize adenoma and polyp detection. The risk of inadequate bowel cleansing is heightened if the patient is older, male, overweight, and has comorbidities, such as diabetes. This post hoc analysis of the combined MORA and NOCT clinical trials explores the efficacy of evening/morning split-dose regimens of NER1006 (PLENVU^®, Norgine Ltd), a 1-liter polyethylene glycol (PEG) bowel preparation, to evaluate its bowel-cleansing efficacy in patients at risk for inadequate cleansing.

METHODS

Patients requiring colonoscopy were randomized to receive evening/morning split-dosing of either NER1006, 2-liter (2L) PEG and ascorbate, or oral sulfate solution (OSS). Bowel-cleansing efficacy was assessed by treatment-blinded central readers using the validated Harefield Cleansing Scale (HCS).

RESULTS

Split-dose NER1006 was associated with high levels of cleansing, ranging between 87.0% and 94.0% across all patient subtypes (n = 551), including patients with obesity or diabetes. However, patients aged >65 years and <45 years showed significantly greater rates of successful cleansing than patients aged 45-65 years (94.0% versus 94.2% versus 87.0%, p = 0.002). The high-risk patient subgroup, which included obese males aged ⩾60 years, had significantly improved overall and high-quality bowel-cleansing success rates of 100% (33/33) and 72.7% (27/33) on the HCS with NER1006, compared with 86.7% (26/30) and 50% (15/30) with the comparator solutions (p = 0.015 and p = 0.033, respectively). In this high-risk subgroup, adenoma detection was greater per patient receiving NER1006 versus the comparator group (1.82 versus 0.93, p = 0.041). NER1006 was the only treatment that enabled the detection of patients with ⩾5 adenomas [9.1% (3/33) versus 0/30, p = 0.047].

CONCLUSION

NER1006 effectively cleansed a broad range of patients and offered superior bowel cleansing versus 2LPEG/OSS in patients at increased risk of colorectal cancer. Future research should establish whether more effective cleansing also enables improved adenoma detection.

PLAIN LANGUAGE SUMMARY

A low-volume bowel preparation solution to better detect lesions associated with colorectal cancer during colonoscopyColorectal cancer (CRC) is the fourth most commonly diagnosed cancer in the world. Obese men over the age of 65 years are at particularly increased risk of developing CRC. If the changes in their large intestine (colon) could be seen more clearly during a colonoscopy (where a small camera is inserted via the anus to examine the bowels from the inside), patients who need treatment would be diagnosed earlier, thus improving their chances of survival. In this paper we discuss the use of a bowel preparation solution that is more convenient for patients (less to drink) but also cleans bowels more effectively, meaning more lesions are detected than when other solutions are used. This improved cleansing, and thus better visualization, occurred in a range of patients, including those at higher risk of CRC, such as older, overweight men.

Bowel preparation in diabetic patients undergoing colonoscopy

Diabetes mellitus is a risk factor for poor bowel preparation in patients who undergo colonoscopy, because of their decreased intestinal transit and slow gastric emptying. This might lead to neoplastic or preneoplastic lesions being missed, longer procedural time, a higher risk of procedure-related adverse events, significant cost burden, patient dissatisfaction, and the need for a repeat colonoscopy. Multiple strategies have been suggested to improve bowel preparation in these patients. Proposed pharmacologic strategies include adding magnesium citrate, bisacodyl, lubiprostone or pyridostigmine. Non-pharmacologic strategies include preferential procedure scheduling or using a diabetes-specific preparation protocol. In this article, we present a comprehensive review of the literature and provide specific recommendations to general practitioners and gastroenterologists for improving bowel preparation in patients with diabetes.

Effect of Body Size on Quality of Bowel Preparation Among Patients Experiencing Colonoscopy

The body size of patients is considered to have an impact on the quality of bowel preparation. The aim of this study was to determine the effect of body mass index (BMI) on bowel preparation and prediction of unprepared patients who underwent colonoscopies. A retrospective study was undertaken with data retrieved from health records at the Center for Gastroenterology and Hepatology in Sulaymaniyah City of 12,527 colonoscopies carried out between February 2012 and December 2018. From the 12,527 records, a total of 9,659 colonoscopy examinations were included in this study. The results showed 21.3% unacceptable colon preparations: 15% poor and 6.3% inadequate. Patients with BMI of 25 and greater accounted for 36.1%. No significant association was found between increased BMI with inadequate preparation (odds ratio [OR]: 1.104, 95% confidence interval [CI]: 0.869-1.401, p value .418 and OR: 0.988, 95% CI: 0.813-1.201, p value .903). However, inadequate preparation could be associated with underweight females, who report constipation, and the elderly. Although there has been shown to be in practice an adverse bias toward patients with a high BMI, this study has shown that an increased body size does not interfere with the quality of bowel preparation or resultant colonoscopy.

Sex difference in bowel preparation quality and colonoscopy time

BACKGROUND/AIMS

The length of colon is known to be longer in females than in males. In addition, the morphology of colon cancer is different between males and females. The aim of this study was to investigate sex differences in Boston bowel preparation score (BBPS) and colonoscopy insertion time.

METHODS

This study retrospectively analyzed medical records and colonoscopy readings of subjects who underwent colonoscopy at Seoul National University Bundang Hospital from March 2015 to April 2018. BPPS was used to evaluate the degree of colon cleanness before colonoscopy. Statistical analysis was performed to compare demographic, clinical, and outcome variables between two groups.

RESULTS

The study group consisted of a total of 12,561 patients (6,148 females and 6,413 males). Mean age was 57.8 ± 13.5 years for females and 57.5 ± 13.8 years for males (p = 0.695). Females showed better bowel preparation than males (mean total score: 7.4 ± 1.8 vs. 7.2 ± 1.9, p = 0.001; total score ≥ 6: 5,340 [86.9%] vs. 5,437 [84.8%], p = 0.001; BBPS ≥ 2 for all segments: 5,048 [82.1%] vs. 5,097 [79.5%], p < 0.001). However, cecal intubation time (8.3 ± 6.2 minutes vs. 6.2 ± 6.1 minutes, p < 0.001) and withdrawal time (7.9 ± 3.5 minutes vs. 7.4 ± 3.1 minutes, p < 0.001) were longer in males.

CONCLUSION

There were sex differences in BBPS, cecal intubation time, and withdrawal time for subjects undergoing colonoscopy.

Comparison of 1L Adjuvant Auxiliary Preparations with 2L Solely Polyethylene Glycol plus Ascorbic Acid Regime for Bowel Cleaning: A Meta-analysis of Randomized, Controlled Trials

The effectiveness of additional usage of adjuvants for bowel preparation is still unclear. This study compared 1L polyethylene glycol plus ascorbic acid with adjuvant drug regimens (1L PEG-AA, lower volume) with 2L polyethylene glycol plus ascorbic acid (2L PEG-A, low volume) to evaluate whether the adjuvants can be used to reduce the standard dosage of purgative further. The PubMed/MEDLINE, EMBASE, Cochrane Library, and Web of Science database were searched for randomized controlled trials (RCTs). The primary outcome was the efficacy of bowel preparation, and the secondary outcomes were patients' tolerability and complication rate. The overall quality of evidence was assessed using the GRADEpro guideline development tool. Five RCTs with a total of 1013 patients from Korea were included. The majority of patients were outpatients from different hospitals. The pooled data showed no significant difference in the adequate bowel preparation rate (89.3% versus 89.4%, RR 1, 95% CI 0.95-1.05, I ² = 47%) as well as in the complication rate (RR for nausea 1.22, 95% CI 0.89-1.65, I ² = 49%; RR for bloating 0.96, 95% CI 0.73-1.28, I ² = 0%; RR for vomiting 0.69, 95% CI 0.32-1.50, I ² = 33%; RR for abdominal pain 1.01, 95% CI 0.61-1.69, I ² = 0%). But a significantly higher willingness rate was observed in the lower volume (85.1% versus 67.9%, RR 1.25, 95% CI 1.14-1.38, I ² = 46%). The quality of primary outcome evidence was moderate. The findings of this meta-analysis revealed that 1L PEG-AA may be a viable alternative to 2L PEG-A, with comparable effectiveness, better patient preference, and no statistically significant adverse event occurrence.

Impact of opioid use on patients undergoing screening colonoscopy according to the quality of bowel preparation

Aims

Constipation associated with opioid therapy for chronic pain may negatively impact colonoscopy success. This retrospective, observational study using administrative data and electronic medical records evaluated the impact of opioid use on colonoscopy outcomes.

Methods and Results

Procedural codes were used to identify patients who had a screening colonoscopy at two Henry Ford Health System centers (January 2015–December 2016). All patients had completed a standard uniform bowel preparation protocol. Medication orders and filled prescriptions were used to identify patients with a history of opioid use during the 28 days preprocedure (exposed) and a matched random sample of presumptive opioid nonusers (unexposed). Electronic medical records were reviewed for colonoscopy procedure data and outcomes.

The exposed and unexposed groups included 964 and 1054 patients, respectively. Inadequate bowel preparation was significantly more common in the exposed versus unexposed group (18.5% vs 12.7%; P < 0.001). In the exposed and unexposed groups, 97.1 and 98.0% of colonoscopy procedures were completed, respectively (P = nonsignificant). Total procedure time was slightly increased for the exposed versus unexposed group (23.8 vs 22.5 min; P = 0.039). Polyp identification and cancer diagnosis were similar between groups. Prolonged sedation occurred in three patients in the exposed group and none in the unexposed group. Procedural complications were rare, but the incidence was significantly greater in the exposed versus unexposed group (1.3% vs 0.2%; P < 0.01).

Conclusions

Opioid exposure was associated with significant reductions in the quality of preprocedure bowel preparation and an increased risk of complications in patients undergoing colonoscopy.

The importance of colonoscopy bowel preparation for the detection of colorectal lesions and colorectal cancer prevention

Background and study aims  Colonoscopy for colorectal cancer (CRC) screening has reduced CRC incidence and mortality and improved prognosis. Optimal bowel preparation and high-quality endoscopic technique facilitate early CRC detection. This review provides a narrative on the clinical importance of bowel preparation for colonoscopy and highlights available bowel preparations. Methods  A PubMed search was conducted through June 2019 to identify studies evaluating clinical outcomes, efficacy, safety, and tolerability associated with bowel preparation for CRC screening-related colonoscopy. Results  Selecting the optimal bowel preparation regimen is based on considerations of efficacy, safety, and tolerability, in conjunction with individual patient characteristics and preferences. Available bowel preparations include high-volume (4 L) and low-volume (2 L and 1 L), polyethylene glycol (PEG) solutions, sodium sulfate, sodium picosulfate/magnesium oxide plus anhydrous citric acid, sodium phosphate tablets, and the over-the-counter preparations magnesium citrate and PEG-3350. These preparations may be administered as a single dose on the same day or evening before, or as two doses administered the same day or evening before/morning of colonoscopy. Ingesting at least half the bowel preparation on the day of colonoscopy (split-dosing) is associated with higher adequate bowel preparation quality versus evening-before dosing (odds ratio [OR], 2.5; 95 % confidence interval [CI], 1.9-3.4). Conclusions  High-quality bowel preparation is integral for optimal CRC screening/surveillance by colonoscopy. Over the last 30 years, patients and providers have gained more options for bowel preparation, including low-volume agents with enhanced tolerability and cleansing quality that are equivalent to 4 L preparations. Split-dosing is preferred for achieving a high-quality preparation.

A 3-day low-fibre diet does not improve colonoscopy preparation results compared to a 1-day diet: A randomized, single-blind, controlled trial

Background

Although a 1-day low-fibre diet before colonoscopy is currently recommended, some endoscopists prescribe a 3-day diet.

Objective

The objective of this study was to compare the influence of a 3-day versus a 1-day low-fibre diet on bowel preparation quality, patient tolerability and adherence.

Methods

Outpatients scheduled for total colonoscopy were randomized in two groups, 3-day versus 1-day low-fibre diet, performing a 4-litre polyethylene glycol split-dose. The primary outcome was a reduction of inappropriate preparations in the 3-day low-fibre diet arm from 15% to 5% (bowel preparation was assessed by the Boston Bowel Preparation Scale). Secondary outcomes were adherence to, difficulty to perform, difficulty to obtain and willingness to repeat the diet. Intention-to-treat (ITT) and per-protocol (PP) analyses were conducted for the primary outcome.

Results

A total of 412 patients were randomized (206 per group). Bowel preparation quality was similar between groups. On ITT analysis (n = 412), adequate bowel preparation was 91.7% (3-day diet) versus 94.7% (1-day diet), p = 0.24 and on PP analysis (n = 400) 93.5% versus 96.5%, respectively, p = 0.16. Difficulty to perform the diet was significantly higher on the 3-day diet, p = 0.04. No differences were found on difficulty to obtain the diet, willingness to repeat the diet, adverse events and intra-colonoscopy findings.

Conclusion

A 3-day low-fibre diet does not bring benefit to the bowel preparation quality and is harder to perform than a 1-day diet.

Augmentation with pre-emptive macrogol-based osmotic laxative does not significantly improve standard bowel preparation in unselected patients: A randomized trial

Background and Aim

The addition of a laxative prior to a standard bowel preparation (BP) has shown variable results in efficacy, safety, and tolerability of the BP. This study compared the efficacy and tolerability of a macrogol-augmented BP (M-BP) with standard BP for routine colonoscopy in unselected patients.

Methods

Adults undergoing outpatient colonoscopy were randomized to either M-BP (one sachet of macrogol-based osmotic laxative (MBOL) twice daily for eight doses prior to standard preparation) or BP (split-dose of polyethylene glycol and sodium picosulfate). Bowel cleansing was assessed using the Ottawa BP scale. Risk factors for poor BP, patient satisfaction, and tolerance were recorded.

Results

This randomized trial was stopped due to futility after 14 months; at that point, 92 subjects were randomized to the study arm and 102 to the control arm. M-BP had a success rate of 71.7% (95% CI: 58.5-82.7%), while the BP had a success rate of 67.7% (95% CI: 54.9-78.8%), with a Pearson χ ² test P-value of 0.639, which exceeded the cut-off for futility (0.313). In subgroup analyses, there were statistically significant decreases in the rates of successful BP in patients taking regular opioids and regular laxatives. Both preparations were well tolerated, with no difference between groups (BP - 5.3% and M-BP - 6.6% P = 0.66).

Conclusion

The addition of MBOL prior to a standard BP in unselected subjects does not significantly improve bowel cleanliness at routine colonoscopy. The role of this laxative in patients at high risk of poor preparation warrants further investigation.

Pilot Study: Neurocognitive Disorders and Colonoscopy in Older Adults

In a preoperative anesthesia setting with integrated neuropsychology for individuals >64 years of age, we completed a pilot study examining the association between neurocognitive disorders with frequency of missed colonoscopies and quality of bowel preparation (prep). Gastroenterologists completed the Boston Bowel Preparation Scale (BBPS) for each patient. Of 47 older adults seen in our service, 68% met criteria for neurocognitive disorders. All individuals failing to attend the colonoscopy procedure had met criteria for major neurocognitive disorder. Poor bowel prep was also identified in 100% of individuals with major neurocognitive disorder and 28% of individuals with mild neurocognitive disorder. Our pilot data suggest that, in high-risk individuals, the presence of neurocognitive disorders is risk factors for missed appointments and inadequate bowel prep. These pilot data provide reference statistics for future intervention protocols.