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

Applying machine learning to predict bowel preparation adequacy in elderly patients for colonoscopy: development and validation of a web-based prediction tool

BACKGROUND

Adequate bowel preparation is crucial for effective colonoscopy, especially in elderly patients who face a high risk of inadequate preparation. This study develops and validates a machine learning model to predict bowel preparation adequacy in elderly patients before colonoscopy.

METHODS

The study adhered to the TRIPOD AI guidelines. Clinical data from 471 elderly patients collected between February and December 2023 were utilized for developing and internally validating the model, while 221 patients' data from March to June 2024 were used for external validation. The Boruta algorithm was applied for feature selection. Models including logistic regression, light gradient boosting machines, support vector machines (SVM), decision trees, random forests, and extreme gradient boosting were evaluated using metrics such as AUC, accuracy, sensitivity, and specificity. The SHAP algorithm helped rank feature importance. A web-based application was developed using the Streamlit framework to enhance clinical usability.

RESULTS

The Boruta algorithm identified 7 key features. The SVM model excelled with an AUC of 0.895 (95% CI: 0.822-0.969), and high accuracy, sensitivity, and specificity. In external validation, the SVM model maintained robust performance with an AUC of 0.889. The SHAP algorithm further explained the contribution of each feature to model predictions.

CONCLUSION

The study developed an interpretable and practical machine learning model for predicting bowel preparation adequacy in elderly patients, facilitating early interventions to improve outcomes and reduce resource wastage.

CiteSpace-based visualization analysis of colonoscopy bowel preparation research

BACKGROUND

We hypothesized that the bowel preparation for special populations and artificial intelligence will be the research hotspots in the future, and tested this hypothesis by searching multiple databases for literature related to bowel preparation and using CiteSpace software to analyze research hotspots in this field.

AIM

To analyze the development trend, research hotspots, and frontiers of bowel preparation for colonoscopy in recent 10 years to provide reference for clinical nursing practice and research.

METHODS

The literature related to bowel preparation for colonoscopy published from January 1, 2014 to December 31, 2024 in CNKI, Wanfang, VIP, Sinomed and PubMed, Web of Science, Embase, and Cochrane Library databases was searched. The literature management software Note Express and Microsoft Excel were used to collate the data of the literature, and the visualization analysis was carried out with CiteSpace software.

RESULTS

A total of 2333 Chinese-language papers and 2632 English-language papers were included in this study. The number of domestic publications showed an overall growth trend; however, affected by the coronavirus disease 2019 epidemic, from 2019 to 2022, it was in a stable state. The number of foreign publications showed a slow growth trend after a small fluctuation. Cooperation groups have been formed among authors, but inter-agency cooperation was not close enough. The research hotspots of bowel preparation for colonoscopy mainly focused on adverse reactions, influencing factors, health education, and bowel preparation for special populations. The research frontiers mainly included auxiliary intervention measures for bowel preparation, risk prediction models, and artificial intelligence.

CONCLUSION

The research on bowel preparation for colonoscopy in China still has much room for development. The bowel preparation for special populations, the application of auxiliary interventions, risk prediction models, bowel preparation assessment tools, health education, artificial intelligence, and bowel preparation process optimization may be future research hotspots.

Effect of chewing gum combined with WeChat-enhanced instruction on bowel preparation in constipated patients: a randomized-controlled trial

Background and aims

Constipated patients have higher risk of poor bowel preparation and suffer from dysfunction of the intestinal motor. Chewing gum can stimulate gut motility and enhanced instructions can improve the quality of bowel preparation. The objective of this study was to investigate whether chewing gum combined with WeChat-enhanced instruction can increase the quality of bowel preparation in constipated patients.

Methods

This was a single-center, endoscopist-blinded, randomized-controlled trial. Patients were assigned (1:1) to the chewing gum and WeChat-enhanced instruction (CGW) group and the control group. Patients in both groups received 3 L of polyethylene glycol (PEG) before colonoscopy. Patients in the CGW group were asked to chew one piece of gum for 20 min after drinking each 1 L of PEG and received enhanced instruction via WeChat the day before colonoscopy. The quality of the bowel preparation (primary outcome), adenoma and/or polyp detection rate (ADR/PDR), number of polyps and/or adenomas, procedure time, and adverse events were compared.

Results

A total of 115 patients were finally analysed, including 60 in the CGW group and 55 in the control group. The proportion of adequate bowel preparation and the Boston Bowel Preparation Scale score were not statistically different between the two groups (76.7% vs 70.9%; 6.80 ± 1.42 vs 6.40 ± 1.78; both P > 0.05). There was no significant difference in the ADR/PDR and number of polyps and/or adenomas (both P > 0.05). However, there was a significantly higher incidence of nausea in the CGW group than in the control group (33.3% vs 16.4%, P = 0.036).

Conclusions

Chewing gum combined with WeChat-enhanced instruction does not improve the quality of bowel preparation for colonoscopy in constipated patients but does increase the incidence of nausea.

Selected comorbidities increases the likelihood of an incomplete colonoscopy during colorectal cancer screening

OBJECTIVE

The risk of incomplete colonoscopy is associated with demographic factors and general comorbidity. However, focus on specific comorbidities is limited. This study aimed to investigate the association between selected comorbidities and incomplete colonoscopy in colorectal cancer (CRC) screening.

METHODS

This register-based study included 71,973 Danish screening participants, undergoing colonoscopy after positive fecal immunochemical test. The selected comorbidities were divided into hematological disease, endocrine disease (nondiabetes), endocrine disease (diabetes related), upper gastrointestinal (GI) disease, lower GI disease, other diseases of digestive system, hepatobiliary and pancreatic (HBP) disease, CRC, intraabdominal cancer (except CRC), and mental disease. Outcomes were incomplete colonoscopy due to poor bowel preparation and other reasons. Multivariate logistic regression models were applied.

RESULTS

Of 5,428 (7.5%) incomplete colonoscopies, 2,625 (3.6%) were due to poor bowel preparation and 2,803 (3.9%) due to other reasons. Individuals with specific comorbidities were compared to those without, exhibiting varying odds ratios (OR) for incomplete colonoscopy. For poor bowel preparation, ORs were 1.20 (95%CI: 1.04;1.39), 1.43 (95%CI: 1.30;1.56), 1.86 (95%CI: 1.66;2.09), 1.27 (95%CI: 1.12;1.43), and 1.64 (95%CI: 1.47;1.83) for hematological, endocrine (nondiabetes), endocrine (diabetes related), HBP, and mental disease, respectively, and 1.29 (95%CI: 1.09;1.52) for intraabdominal cancer (except CRC). Incomplete colonoscopies due to other reasons showed ORs of 1.24 (95%CI: 1.08;1.43), 1.18 (95%CI: 1.03;1.36), 1.19 (95%CI: 1.05;1.35), and 1.30 (95%CI: 1.15;1.47) for hematological, endocrine (diabetes related), HBP, and mental disease, respectively, and 1.35 (95%CI: 1.15;1.60) for intra-abdominal cancer (except CRC).

CONCLUSION

Participants with specific comorbidities had significantly higher probability of having an incomplete colonoscopy, suggesting that certain comorbidities could be used prospectively as a predictive factor.

Optimizing bowel preparation quality for colonoscopy: consensus recommendations by the US Multi-Society Task Force on Colorectal Cancer

This document is an update to the 2014 recommendations for optimizing the adequacy of bowel cleansing for colonoscopy from the US Multi-Society Task Force on Colorectal Cancer, which represents the American College of Gastroenterology, the American Gastroenterological Association, and the American Society for Gastrointestinal Endoscopy. The US Multi-Society Task Force developed consensus statements and key clinical concepts addressing important aspects of bowel preparation for colonoscopy. The majority of consensus statements focus on individuals at average risk for inadequate bowel preparation. However, statements addressing individuals at risk for inadequate bowel preparation quality are also provided. The quality of a bowel preparation is defined as adequate when standard screening or surveillance intervals can be assigned based on the findings of the colonoscopy. We recommend the use of a split-dose bowel preparation regimen and suggest that a 2 L regimen may be sufficient. A same-day regimen is recommended as an acceptable alternative for individuals undergoing afternoon colonoscopy, but we suggest that a same-day regimen is an inferior alternative for individuals undergoing morning colonoscopy. We recommend limiting dietary restrictions to the day before a colonoscopy, relying on either clear liquids or low-fiber/low-residue diets for the early and midday meals. We suggest the adjunctive use of oral simethicone for bowel preparation before colonoscopy. Routine tracking of the rate of adequate bowel preparations at the level of individual endoscopists and at the level of the endoscopy unit is also recommended, with a target of >90% for both rates.

Optimizing Bowel Preparation Quality for Colonoscopy: Consensus Recommendations by the US Multi-Society Task Force on Colorectal Cancer

This document is an update to the 2014 recommendations for optimizing the adequacy of bowel cleansing for colonoscopy from the US Multi-Society Task Force on Colorectal Cancer, which represents the American College of Gastroenterology, the American Gastroenterological Association, and the American Society for Gastrointestinal Endoscopy. The US Multi-Society Task Force developed consensus statements and key clinical concepts addressing important aspects of bowel preparation for colonoscopy. The majority of consensus statements focus on individuals at average risk for inadequate bowel preparation. However, statements addressing individuals at risk for inadequate bowel preparation quality are also provided. The quality of a bowel preparation is defined as adequate when standard screening or surveillance intervals can be assigned based on the findings of the colonoscopy. We recommend the use of a split-dose bowel preparation regimen and suggest that a 2 L regimen may be sufficient. A same-day regimen is recommended as an acceptable alternative for individuals undergoing afternoon colonoscopy, but we suggest that a same-day regimen is an inferior alternative for individuals undergoing morning colonoscopy. We recommend limiting dietary restrictions to the day before a colonoscopy, relying on either clear liquids or low-fiber/low-residue diets for the early and midday meals. We suggest the adjunctive use of oral simethicone for bowel preparation before colonoscopy. Routine tracking of the rate of adequate bowel preparations at the level of individual endoscopists and at the level of the endoscopy unit is also recommended, with a target of >90% for both rates.

Optimizing Bowel Preparation Quality for Colonoscopy: Consensus Recommendations by the US Multi-Society Task Force on Colorectal Cancer

This document is an update to the 2014 recommendations for optimizing the adequacy of bowel cleansing for colonoscopy from the US Multi-Society Task Force on Colorectal Cancer, which represents the American College of Gastroenterology and the American Society for Gastrointestinal Endoscopy. The US Multi-Society Task Force developed consensus statements and key clinical concepts addressing important aspects of bowel preparation for colonoscopy. The majority of consensus statements focus on individuals at average risk for inadequate bowel preparation. However, statements addressing individuals at risk for inadequate bowel preparation quality are also provided. The quality of a bowel preparation is defined as adequate when standard screening or surveillance intervals can be assigned based on the findings of the colonoscopy. We recommend the use of a split-dose bowel preparation regimen and suggest that a 2 L regimen may be sufficient. A same-day regimen is recommended as an acceptable alternative for individuals undergoing afternoon colonoscopy, but we suggest that a same-day regimen is an inferior alternative for individuals undergoing morning colonoscopy. We recommend limiting dietary restrictions to the day before a colonoscopy, relying on either clear liquids or low-fiber/low-residue diets for the early and midday meals. We suggest the adjunctive use of oral simethicone for bowel preparation before colonoscopy. Routine tracking of the rate of adequate bowel preparations at the level of individual endoscopists and at the level of the endoscopy unit is also recommended, with a target of >90% for both rates.

Remedial colon hydrotherapy device enema as a salvage strategy for inadequate bowel preparation for colonoscopy: A retrospective cohort study

OBJECTIVE

Colon hydrotherapy devices serve as a physiotherapeutic modality to manage colonic disorders by promoting intestinal peristalsis and enhancing gastrointestinal functionality. This study aims to assess and compare the effectiveness, safety, and tolerability of two remedial strategies for inadequate bowel preparation: colon hydrotherapy device enema and oral polyethylene glycol electrolyte powder.

METHODS

A retrospective analysis was performed on 109 patients who failed to adequately prepare for colonoscopy. These patients received remedial bowel preparation on the same day as their procedure, with 55 undergoing colon hydrotherapy enema and 54 receiving oral polyethylene glycol electrolyte powder. Patient satisfaction and tolerance were evaluated through telephone follow-up. Key metrics included the Boston Bowel Preparation Scale scores, preparation time, incidence of adverse reactions, and patient tolerance and satisfaction.

RESULTS

No significant differences were observed in baseline characteristics between groups (P >  0.05). The Boston Bowel Preparation Scale scores for the entire colon were 7 (3) in the hydrotherapy group and 6.5 (1) in the oral group (z =  -2.075, P =  0.038). Notably, scores for the left colon were significantly higher in the hydrotherapy group [3 (1) vs. 2 (0), z =  -5.586, P <  0.001]. The hydrotherapy group also exhibited a shorter preparation time [80 (20) min vs. 92.5 (20) min, z =  -3.961, P <  0.001] and a lower incidence of adverse effects (36.4% vs. 88.9%, χ² =  32.035, P <  0.001). Patient satisfaction metrics, including re-selection rates and tolerance of side effects, were significantly higher in the hydrotherapy group.

CONCLUSIONS

The colon hydrotherapy device enema is an effective, efficient, and well-tolerated method for bowel cleansing, demonstrating a low incidence of adverse events. It is recommended as an effective and safe remedial therapy for patients with inadequate bowel preparation prior to colonoscopy.

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.

Diagnostic performance and clinical outcomes of computed tomography colonography in a sick inpatient population

PURPOSE

Though prior studies have proven CTC's efficacy in outpatients, its utility in the inpatient setting has not been studied. We evaluated the efficacy of a modified CTC protocol in the inpatient setting, primarily for patients awaiting organ transplantation.

METHODS

This retrospective study compared a group of inpatient CTCs from 2019 to 2021 and a randomly selected, age-matched 2:1 control group of outpatient CTCs. Both groups were assessed based on established criteria from literature.

RESULTS

10 % (63/652) of CTCs were performed in the inpatient setting, of which 29 were excluded, yielding 34 inpatient cases. 90 % (589/652) of CTCs were performed in the outpatient setting, from which 68 randomly selected, age-matched patients were selected as controls. Significantly more (24 %, 8/34) inpatients expired due to extracolonic causes (vs. 1 %, 1/68 outpatients, p < 0.05). 62 % (21/34) of inpatient CTCs were reported as diagnostic (vs. 74 %, 50/68 outpatient, p = 0.22). Significantly more inpatients (12 %, 4/34) than outpatients (1 %, 1/68) were unable to tolerate two imaging positions (p = 0.02). Subsequent colonoscopy was performed in 24 % (8/34) of inpatients, revealing pathologies including colonic polyps and non-bleeding ulcers. Inpatient CTCs had lower average quality scores, significant for one reviewer (p = 0.009-0.054). Inpatients had a larger number of segments with: >25 % residual fluid (1.22-1.28 inpatients vs. 0.60-0.73 outpatients, p = 0.003-0.026) and inadequate fluid tagging (1.10 inpatients vs. 0.49 outpatients, p = 0.046-0.0501). Distention was not significantly different between groups (p = 0.317-0.410).

CONCLUSION

Quality of inpatient CTC was inferior to outpatient CTCs across several metrics. 24 % undergoing inpatient CTC died of extracolonic causes within 22 months, and most did not have findings warranting intervention, questioning the value of this difficult exam in this patient population. Routine CT may be sufficient to exclude large or metastatic colonic lesions precluding transplant.

The Effectiveness of Additional Information Provided Before Colonoscopy Regarding Bowel Preparation

Background: This study aimed to evaluate the effect of patient education provided through one-on-one verbal instruction supported by visual media tools for bowel preparation prior to a colonoscopy procedure. Materials and Methods: This prospective study included patients who underwent colonoscopy in our clinic's endoscopy unit between April 2024 and August 2024. The study design included two groups: the control group (CG), wherein patients scheduled for a colonoscopy received standard information about the procedure at the outpatient clinic, and the information group (IG), wherein patients were invited to the clinic 5 days before the procedure and received an interactive education session lasting approximately 10 min in addition to the standard information. The adequacy of bowel preparation was evaluated using the Boston Bowel Preparation Scale (BBPS). Results: This study included 228 patients, with 114 patients in each group. Of the patients, 137 were male (60.08%) and 91 were female (39.92%). The mean age of the patients was 49.41 ± 15.04 years, the mean BMI was 27.48 ± 4.23, and the mean BBPS score was 7.38 ± 1.96. The mean BBPS score of the patients in the IG and CG was 7.76 ± 1.84 and 7.00 ± 2.01, respectively, and there was a statistically significant difference between the two groups (p = 0.003). Conclusions: Additional information provided prior to the colonoscopy procedure was identified as an effective parameter on adequate bowel preparation.

Derivation and validation of a prediction model for inadequate bowel preparation in Chinese outpatients

The quality of bowel preparation is an important factor in the success of colonoscopy. However, multiple influencing factors that function together can lead to inadequate bowel preparation. The main objective of this study was to explore the specific factors that affect the quality of bowel preparation, with the goal of deriving and validating a predictive model for inadequate bowel preparation in Chinese outpatients. A prospective observational study. We conducted a prospective study in a tertiary hospital in Zhejiang Province that included elective colonoscopy outpatients treated between December 15, 2022 and August 12, 2023. Clinical data related to the patient characteristics and patient bowel preparation were collected to analyze the risk factors of inadequate bowel preparation in outpatients. The quality of bowel preparation was assessed by using the Boston bowel preparation scale (BBPS). Inadequate bowel preparation was defined as a total BBPS score of < 6 or any segment score of < 2. The predictive model was constructed based on multivariate logistic regression, and the discrimination and calibration of the prediction model were evaluated via internal and external validation; additionally, a clinical decision curve was drawn to evaluate the clinical utility of the model. A total of 1314 patients were included from December 15, 2022 through May 31, 2023 (derivation cohort, n = 1035) and from June 1 through August 12, 2023 (external validation cohort, n = 279). Inadequate bowel preparation occurred in 260 of 1035 patients in the derivation cohort (25.1%). Multivariate analysis identified that male sex (OR = 1.690, 95% CI: 1.242-2.300), diabetes (OR = 1.769, 95% CI: 1.059-2.954), constipation (OR = 2.375, 95% CI: 1.560-3.617), history of colorectal surgery (OR = 2.915, 95% CI: 1.455-5.840), a high fiber diet used at 24 h before examination (OR = 2.662, 95% CI: 1.636-4.334) and the time interval from the end of the bowel preparation to the start of the colonoscopy (PC) >5 h (OR = 2.471, 95% CI: 1.814-3.366) were independent risk factors. We derived a model to identify patients with inadequate cleansing by using data from patients in the derivation cohort and tested it in the validation cohort. The area under the curve (AUC) was 0.704 (95% CI: 0.667-0.741), with a calibration value of p = 0.632 in the derivation cohort. Bootstrap cross-validation showed a good model calibration condition. For the validation cohort, the AUC was 0.704 (95% CI: 0.628-0.779), and the calibration value was p = 0.376. We identified the influencing factors of outpatient bowel cleansing that are associated with patient clinical characteristics and bowel preparation-related behaviors. A model was constructed and validated to identify patients who were at high risk of inadequate bowel preparation by using six simple variables, which included male sex, diabetes, constipation, history of colorectal surgery, a high fiber diet used at 24 h prior to examination, and PC > 5 h. The clinical decision curve showed that the constructed prediction model has some clinical utility based on results from the derivation cohort and validation cohort.

Cirrhosis and Portal Hypertension Worsen Bowel Preparation for Screening Colonoscopy

BACKGROUND

Colonoscopy is a diagnostic and therapeutic procedure that reduces colorectal cancer incidence and mortality but requires adequate bowel cleansing for high-quality examination. Past studies have suggested cirrhosis as a risk factor for worse bowel preparation.

METHODS

We carried out a match-controlled retrospective study evaluating patients with and without cirrhosis who underwent outpatient screening colonoscopies to assess the effect of cirrhosis and portal hypertension complications on preparation quality and endoscopic measures. We also did a subgroup analysis excluding patients with obesity.

RESULTS

We examined 1464 patients with cirrhosis and matched controls. Cirrhotic patients had lower mean Boston Bowel Preparation Scale (BBPS) scores and slower cecal intubation times. We found a single point increase in the Model for End-stage Liver Disease (MELD) score, as well as ascites, hepatic encephalopathy, and variceal hemorrhage were all associated with a longer cecal intubation time. Subgroup analysis excluding patients with obesity again found a significantly lower BBPS score and longer cecal intubation time while also finding a 24% drop in polyp detection.

CONCLUSIONS

Patients with cirrhosis have worse BBPS scores and longer cecal intubation times. Nonobese cirrhotic patients additionally have a lower polyp detection rate. Portal hypertension complications were associated with worsened preparation quality and longer cecal intubation times. Each incremental increase in MELD score lengthened cecal intubation time. These findings support a more aggressive bowel preparation strategy for patients with cirrhosis, especially patients with severe disease or portal hypertension complications.

Interventions to improve bowel cleansing in colonoscopy

INTRODUCTION

Suboptimal bowel preparation adversely affects colonoscopy quality, increases healthcare costs, and prolongs waiting time. The primary contributing factors include poor tolerance to the preparation solutions, noncompliance with prescribed instructions, and suboptimal efficacy of the bowel cleansing solution itself.

AREAS COVERED

This review examined the predictive factors associated with suboptimal bowel preparation and discussed interventions aimed at improving bowel cleansing. It also provides evidence-based practical algorithms supplemented by insights from our own clinical experience. Relevant topics were reviewed using resources from the PubMed database.

EXPERT OPINION

Although current bowel preparation protocols are effective for the majority of patients, a significant proportion still present challenges for optimal preparation. These patients may benefit from personalized strategies tailored to the specific causes of preparation failure. Conducting a thorough interview is crucial for identifying the reasons for failure, particularly in patients who have previously experienced suboptimal preparation during colonoscopy. In colonoscopy-naïve patients, it is essential to assess the risk of suboptimal preparation. In both cases, interventions should be customized to either address the identified causes in the former group or employ preventive strategies to reduce the likelihood of failure in the latter.

Risk Factors for Inadequate Bowel Preparation in Colonoscopy: A Comprehensive Systematic Review and Meta-Analysis

INTRODUCTION

Inadequate bowel preparation (IBP) before colonoscopy remains a common problem. This meta-analysis aimed to assess the risk factors associated with IBP.

METHODS

We searched multiple databases for studies that assessed risk factors for IBP after adjustment and reported the data as adjusted odds ratios with 95% confidence intervals. Meta-analyses were conducted using a random-effects model, and pooled adjusted odds ratios for risk factors reported in ≥ 3 studies were constructed.

RESULTS

One hundred fifty-four studies with 358,257 participants were included. We analyzed 48 unique risk factors. Sociodemographic predictors of IBP were Medicaid insurance, obesity, current tobacco use, age ≥ 65 years, Black race, low education level, male sex, and unmarried status. Comorbidity-related predictors of IBP were any psychiatric disease, cirrhosis, American Society of Anesthesiologists (ASA) class ≥ 3, poor functional status, constipation, diabetes, previous abdominopelvic surgery, and hematochezia. Medication-related predictors of IBP were tricyclic antidepressants, antidepressants, opioids, nontricyclic antidepressants, and calcium channel blockers. Preparation/procedure-related predictors of IBP were brown liquid rectal effluent, any incomplete bowel preparation (BP) intake, lack of split-dose BP, increased BP-to-defecation interval, any nonadherence to dietary instructions, increased BP-to-colonoscopy interval, any BP intolerance, previous IBP, and inpatient status. Although afternoon colonoscopy was a predictor of IBP, subgroup analysis of prospective studies revealed no significant association.

DISCUSSION

Our meta-analysis focused on adjusted risk factors to provide precise estimates of the most important risk factors for IBP. Our findings could help develop a validated prediction model to identify high-risk patients for IBP, improve colonoscopy outcomes, reduce the need for repeat colonoscopies, and reduce associated healthcare costs.

Bowel preparation with linaclotide and 1 L polyethylene glycol plus ascorbic acid prior to colonoscopy in chronic constipated patients

BACKGROUND AND AIMS

Information on effective bowel preparation (BP) methods for patients with constipation is limited. We recently reported the efficacy of 1 L polyethylene glycol plus ascorbic acid (PEG-Asc) combined with senna for BP; however, this regimen was insufficient in patients with constipation. We hypothesized that the addition of linaclotide, which is approved for the treatment of chronic constipation, to 1 L PEG-Asc would yield results superior to those of senna in patients with constipation.

METHODS

This was a retrospective, single-center study that included outpatients with constipation who underwent BP prior to colonoscopy between March and December 2019 (receiving 1 L PEG-Asc with 24 mg senna) and between January and October 2020 (receiving 1 L PEG-Asc with 500 mg linaclotide).

RESULTS

A total of 543 patients with constipation were included, of whom 269 received linaclotide and 274 received senna. The rate of inadequate BP was significantly lower (11% vs 20%, p < 0.01) and the adenoma detection rate was significantly higher (54% vs 45%, p = 0.04) in the linaclotide group than in the senna group. Multivariate analysis revealed that the linaclotide regimen significantly reduced the risk of inadequate BP (odds ratio = 0.36, 95% confidence interval = 0.21-0.60, p < 0.01).

CONCLUSIONS

The linaclotide regimen significantly increased BP efficacy and the adenoma detection rate compared with the senna regimen without reducing tolerability and is therefore a promising new option for BP in patients with constipation.

Patient Compliance With Bowel Preparation for Elective Colorectal Surgery

INTRODUCTION

Studies show that mechanical bowel preparation (MBP) plus oral antibiotics (OAs) is associated with decreased rates of postoperative complications after elective colorectal surgery. However, there is a lack of literature regarding patient compliance with bowel preparation (BP).

MATERIALS AND METHODS

Patients undergoing elective colorectal surgeryfrom April 2020 to March 2022 at a tertiary care academic hospital (TCAH) and safety net hospital (SNH) were administered a BP compliance survey. Patients were compared on the basis of hospital setting and completeness of BP using student's t-tests and Fisher's exact tests, as appropriate.

RESULTS

105 patients were included as follows: 55 from the TCAH and 50 from the SNH. The median age was 59. 45.7% were female. TCAH had a higher proportion of White patients (36.4% versus 0%), while the SNH had a higher proportion of Hispanic patients (78% versus 10.9%). Most patients at the TCAH reported English as their primary language (80% versus 28%), while most patients at the SNH spoke primarily Spanish (60% versus 7.3%). In total, 88.6% (n = 93) of patients completed the MBP- 87.3% at the TCAH and 90% at the SNH (P = 0.764). 86.7% took all three doses of OA. Compared to the SNH patients, a smaller percentage of TCAH patients took all doses of OA (78.2% versus 96%, P = 0.009). Overall, 45.7% of patients reported adverse symptoms with BP. The only patient factor associated with a complete bowel preparation was SNH setting (P = 0.024).

CONCLUSIONS

Overall, almost 90% of patients were compliant with both MBP and OA. Compliance with OA among patients at the TCAH was significantly lower compared to patients at the SNH. An SNH setting was associated with completing a BP. Individual compliance is likely impacted by both institutional practices and patient factors.

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.

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).

Efficacy of linaclotide in combination with polyethylene glycol for bowel preparation in Chinese patients undergoing colonoscopy polypectomy: protocol for a randomised controlled trial

BACKGROUND

Adequate bowel preparation is essential for successful colonoscopy and polypectomy procedures. However, a significant proportion of patients still exhibit suboptimal bowel preparation, ranging from 18% to 35%. The effectiveness of bowel preparation agents can be hampered by volume and taste, adversely affecting patient compliance and tolerance. Therefore, exploring strategies to minimise laxative volume and improve patient tolerance and adherence is imperative to ensure optimal bowel preparation quality.

METHODS AND ANALYSIS

This study is a two-arm, single-blinded, parallel-group randomised controlled trial designed to compare the efficacy of 2 L polyethylene glycol (PEG) combined with linaclotide with 4 L PEG in bowel cleansing. A total of 422 participants will be randomly assigned in a 1:1 ratio to either the intervention group (2 L PEG combined with 580 µg linaclotide) or the control group (4 L PEG). The primary outcome measure is bowel cleansing efficacy, which is assessed using the Boston Bowel Preparation Scale. Secondary outcomes include evaluating the tolerability and safety of the bowel preparation regimens, bowel diary assessments, postpolypectomy complications (such as bleeding and perforation) and the size and number of removed polyps.

ETHICS AND DISSEMINATION

The study has received approval from the Clinical Research Ethics Committee of The First Affiliated Hospital, Zhejiang University School of Medicine. The findings of this trial will serve as a valuable resource for clinicians and patients undergoing colonoscopy polypectomy by guiding the selection of appropriate bowel preparation regimens. Study findings will be disseminated to participants, presented at professional society meetings, and published in peer-reviewed journals. This trial was registered on the Chinese Clinical Trial Registry with registration number ChiCTR2300075410.

Online Educational Module Improves Knowledge of Nurses on Bowel Preparation for Colonoscopy

The effectiveness of colonoscopy is limited by the adequacy of bowel preparation. Nurses are essential in providing bowel cleansing agents and instructions for hospitalized patients before colonoscopy. This study aims to assess and improve the knowledge of nurses on bowel preparation for inpatient colonoscopy. Participants were asked to complete the survey before and after completing an educational module. The module and survey questions were placed in the NetLearning environment of the hospital intranet. A minimum post-test score of 80% was required to pass the course. A total of 1,107 nurses participated in the survey. Overall, the average score improved from 87% to 93% after the module (p < .0495). Knowledge of the different ways of consuming bowel cleansing agents improved from 54.3% to 83.6% (p = .0001). Only 56.2% of nurses knew how to carry out a split-dose bowel preparation regimen, which increased to 80.1% after the educational module (p = .0001). Nurses' knowledge about the different ways of consuming bowel cleansing agents before colonoscopy and the split-dose regimen is inadequate. A simple online educational module significantly improved the knowledge of nurses on bowel preparation for colonoscopy.

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.

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.

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.

Real-word evaluation of differences in bowel preparation for colonoscopy between the digestive and the non-digestive physicians: A retrospective study

Introduction

Using real-world data, we compared the quality of bowel preparation instructed by the digestive and non-digestive physicians in outpatients for colonoscopy and identified potential risk factors.

Methods

This was a retrospective study based on real-world data, which were collected from the Ningbo First Hospital in China from December 2019 to October 2020. Outpatients included were classified into the digestive and the non-digestive physician groups according to the referring physician. The primary outcome was adequate bowel preparation measured by the Boston Bowel Preparation Scale (BBPS), namely, a BBPS score of 2 or higher in any colonic segment and a total score ≥ 6. Secondary outcomes included the total mean BBPS scores and possible risk factors associated with poor bowel preparation.

Results

There were 671 outpatients included, with 392 in the digestive physician group and 279 in the non-digestive physician group. Adequate bowel preparation was 84.2% in the digestive physician group and 71.0% in the non-digestive physician group (odds ratio [OR]: 1.50, p &lt; 0.001), and the latter had lower total mean BBPS scores (6.12 ± 1.33 vs. 6.66 ± 1.29, p &lt; 0.001). The non-digestive physician was an independent risk factor according to the multivariate logistic regression analysis (OR: 0.45, p &lt; 0.001).

Conclusion

The quality of bowel preparations instructed by non-digestive physicians was inferior to digestive physicians, which was a factor potentially associated with poor bowel preparation (ClinicalTrials.gov number: NCT04738578).

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.