Meta-Analysis of the Effect of Bowel Preparation on Adenoma Detection: Early Adenomas Affected Stronger than Advanced Adenomas

Can an educational video improve the adequacy of bowel preparation for patients undergoing their first colonoscopy? Results of the EBOPS RCT

Background and study aims The aim of this study was to assess the effect of an educational video on the quality of bowel preparation of patients from a UK population attending for their first colonoscopy. Patients and methods A prospective, endoscopist-blinded trial with 1:1 allocation was performed. Patients referred for their first colonoscopy were recruited between February 2019 and December 2019. All participants were prescribed Moviprep and received the trial site's standard written bowel preparation instructions, with the intervention group also receiving a bespoke educational video. Adequacy of bowel preparation (defined as a Boston Bowel Preparation Scale of ≥2 in each segment of the bowel) and polyp detection rates (PDRs) were compared. Fisher's chi squared test was utilized with P <0.05 as the threshold for significance. Results A total of 509 participants completed the trial from six centers; 251 were randomized to the intervention group. The mean age was 57 years and 52.3% were female. The primary endpoint was met with an adequacy rate of 216 of 251 (86.1%) in the intervention group, compared with 205 of 259 (79.1%) in the control group ( P <0.05, odds ratio [OR] 1.626, 95% CI 1.017-2.614). The PDR was significantly higher in the intervention group (39% vs 30%, OR 1.51, 95% CI 1.04-2.19, P <0.05). Conclusions An educational video leads to improved bowel preparation for patients attending for their first colonoscopy, and is also associated with greater detection of polyps. Widespread adoption of an educational video incurs minimal investment, but would reduce the number of inadequate procedures, missed pathology, and the cost that both these incur.

Efficacy of 1 L polyethylene glycol plus ascorbate versus 4 L polyethylene glycol in split-dose for colonoscopy cleansing in out and inpatient: A multicentre, randomized trial (OVER 2019)

BACKGROUND AND AIMS

Adequate bowel cleansing is essential for colonoscopy quality. A novel 1 L polyethylene glycol plus ascorbate (1 L PEG+ASC) solution has been recently introduced. Nevertheless, the efficacy of 1 L PEG+ASC as compared to that of high-volume bowel preparation in both inpatients and outpatients is still unclear.

PATIENTS AND METHODS

This single-blinded, non-inferiority study randomized patients undergoing colonoscopy to receive split-dose 1 L PEG+ASC or 4 L PEG. The primary endpoint was the overall cleansing success. Secondary endpoints were excellent cleansing and high-quality cleansing of the right colon, as well as lesions detection rate, patient compliance, tolerability and safety.

RESULTS

Overall, 478 patients were randomized to 1 L PEG+ASC (N = 236) or 4 L PEG (N = 242). The 1 L PEG+ASC showed higher cleansing success rate (91.8% vs 83.6%; P=0.01) and a high-quality cleansing of the right colon (52.3% and 38.5%; P=0.004) compared to 4 L PEG. Moreover, 1 L PEG+ASC achieved a higher cleansing success in out-patients (96.3%% vs 88.6%; P=0.018), and a similar success rate in the in-patients (84.7% vs 76.7%; P=0.18). Adenoma detection rate, tolerability and incidence of adverse events were comparable between preparations.

CONCLUSIONS

The 1 L PEG+ASC showed higher efficacy in achieving adequate colon cleansing compared with 4 L PEG, particularly in the right colon. No differences in the tolerability and safety were detected.

An intraprocedural bowel cleansing system for difficult-to-prepare patients-A multicenter prospective feasibility study

BACKGROUND

Adequate bowel preparation is a prerequisite for colonoscopy. However, up to 20% of colonoscopies remain inadequately prepared. Risk factors for inadequate bowel preparation often overlap with those of failed cecal intubation. This study aimed to assess the feasibility of an intraprocedural bowel cleansing system (BCS) in patients with a history of inadequate bowel preparation.

METHODS

Patients (n = 44) with a history of inadequate bowel preparation in the past 2 years were included. After a limited preparation with 300 mL split-dose sodium picosulfate magnesium citrate, additional cleansing during colonoscopy was performed with the BCS. The primary outcome was adequate bowel preparation using the Boston Bowel Preparation Scale (BBPS). Secondary outcomes included cecal intubation rate, procedure times, usability, and safety.

RESULTS

Median BBPS increased from 1-2-2 (IQR 1-2) to 3-3-3 (IQR) (p < 0.0001), with 31.8% and 88.6% of patients adequately prepared before and after using the BCS, respectively (p < 0.0001). Cecal intubation rate was 88.6%. Reasons for incomplete colonoscopy were looping (n = 2), technical failure (n = 1), relative stricture (n = 1), and residual feces (n = 1). In patients with complete colonoscopy, the adequate cleansing rate was 97.5%. Median total procedure time was 26 min, of which 5.3 min were spent on cleaning. General ease of use was scored with a median of 4 out of 5, representing "as good as conventional colonoscopy". No serious adverse events occurred.

CONCLUSIONS

Adequate bowel cleaning can be achieved with an intraprocedural BCS in patients with a history of inadequate bowel preparation, which may reduce repeat colonoscopies and clinical admissions for bowel preparation. However, since these patients more frequently have complicated anatomy (surgical scarring, diverticulosis, etc.), adequate patient selection is advised to avoid incomplete procedures.

Development and validation of a three-dimensional deep learning-based system for assessing bowel preparation on colonoscopy video

Background

The performance of existing image-based training models in evaluating bowel preparation on colonoscopy videos was relatively low, and only a few models used external data to prove their generalization. Therefore, this study attempted to develop a more precise and stable AI system for assessing bowel preparation of colonoscopy video.

Methods

We proposed a system named ViENDO to assess the bowel preparation quality, including two CNNs. First, Information-Net was used to identify and filter out colonoscopy video frames unsuitable for Boston bowel preparation scale (BBPS) scoring. Second, BBPS-Net was trained and tested with 5,566 suitable short video clips through three-dimensional (3D) convolutional neural network (CNN) technology to detect BBPS-based insufficient bowel preparation. Then, ViENDO was applied to complete withdrawal colonoscopy videos from multiple centers to predict BBPS segment scores in clinical settings. We also conducted a human-machine contest to compare its performance with endoscopists.

Results

In video clips, BBPS-Net for determining inadequate bowel preparation generated an area under the curve of up to 0.98 and accuracy of 95.2%. When applied to full-length withdrawal colonoscopy videos, ViENDO assessed bowel cleanliness with an accuracy of 93.8% in the internal test set and 91.7% in the external dataset. The human-machine contest demonstrated that the accuracy of ViENDO was slightly superior compared to most endoscopists, though no statistical significance was found.

Conclusion

The 3D-CNN-based AI model showed good performance in evaluating full-length bowel preparation on colonoscopy video. It has the potential as a substitute for endoscopists to provide BBPS-based assessments during daily clinical practice.

Optimization of colonoscopy quality: Comprehensive review of the literature and future perspectives

Colonoscopy is crucial in preventing colorectal cancer (CRC) and reducing associated mortality. This comprehensive review examines the importance of high-quality colonoscopy and associated quality indicators, including bowel preparation, cecal intubation rate, withdrawal time, adenoma detection rate (ADR), complete resection, specimen retrieval, complication rates, and patient satisfaction, while also discussing other ADR-related metrics. Additionally, the review draws attention to often overlooked quality aspects, such as nonpolypoid lesion detection, as well as insertion and withdrawal skills. Moreover, it explores the potential of artificial intelligence in enhancing colonoscopy quality and highlights specific considerations for organized screening programs. The review also emphasizes the implications of organized screening programs and the need for continuous quality improvement. A high-quality colonoscopy is crucial for preventing postcolonoscopy CRC- and CRC-related deaths. Health-care professionals must develop a thorough understanding of colonoscopy quality components, including technical quality, patient safety, and patient experience. By prioritizing ongoing evaluation and refinement of these quality indicators, health-care providers can contribute to improved patient outcomes and develop more effective CRC screening programs.

Effectiveness and safety of 1-L PEG-ASC versus other bowel preparations for colonoscopy: A meta-analysis of nine randomized clinical trials

BACKGROUND AND AIMS

A 1-L polyethylene glycol plus ascorbate (PEG-ASC) preparation has been recently developed to improve patients' experience in colonoscopy. This meta-analysis aimed to evaluate the effectiveness and safety of 1-L PEG-ASC compared with those of other bowel preparations for colonoscopy.

METHODS

MEDLINE, Embase, Scopus, and the Cochrane Library were systematically searched for randomized controlled trials comparing 1-L PEG-ASC with other bowel preparations published through July 2022. A random-effects model was applied for pooling the results; heterogeneity was expressed as I2.

RESULTS

Nine studies met the inclusion criteria and were included. The analysis showed significantly higher cleansing success (CS) (OR = 1.50; 95% CI = 1.25-1.81; p < 0.01, I2 = 0%) and right-colon high-quality cleansing (HQC) (OR = 1.67; 95% CI = 1.21-2.31; p < 0.01, I2 = 43%) with 1-L PEG-ASC compared to the other preparations. The pooled estimate of the adenoma detection rate (ADR) did not significantly differ between the two groups either in the overall (OR = 1.02; 95% CI = 0.87-1.20; p = 0.79, I2 = 0%) or split-dosing regimen subgroup analysis (OR = 0.99; 95% CI = 0.84-1.18; p = 0.94, I2 = 0%). A significantly higher pooled estimate of the number of patients with adverse events (AEs) (OR = 1.51; 95% CI = 1.23-1.84; p<0.01, I2 = 0%) and incidence of AEs (IRR=1.33; 95% CI = 1.11-1.58; p<0.01, I2 = 71%) was observed with 1-L PEG-ASC than with the other preparations. No serious AEs or deaths occurred.

CONCLUSIONS

Compared to other preparations, 1-L PEG-ASC yielded higher overall CS, higher right-colon HQC rates, and similar ADR. The number of patients with AEs and incidence of the total AEs were significantly higher with 1-L PEG-ASC in the absence of serious AEs.

Determining efficacy of dynamic multimedia bowel preparation instructions versus standard instructions on adenoma detection and patient reported measures (DIGICLEAN trial): a study protocol for a multicentre, colonoscopist-blinded, randomised controlled trial

INTRODUCTION

Colonoscopy plays important roles in bowel cancer screening and treatment. Poor bowel preparation occurs in 20-25% of colonoscopies. This negatively impacts adenoma and sessile serrated lesion detection rates, procedural time, requirement for repeat colonoscopies, healthcare costs and likelihood of patient withdrawal from screening programmes. It is unclear whether a combination of multimedia modalities can improve bowel preparation quality, adenoma detection rates and patient-reported measures in those undergoing colonoscopy assessment.

METHODS

The DIGICLEAN trial is a prospective, parallel, multicentre, colonoscopist-blinded, randomised controlled trial. The trial will enrol 1294 participants aged 45 years and older who are indicated for a colonoscopy as an outpatient with a positive faecal occult blood test, iron deficiency anaemia or rectal bleeding. Participants will be randomised into the interventional arm, where bowel preparation instructions are delivered via a web-based application which uses scheduled short messaging service, regular patient survey assessment, email and videos; or the control arm, where routine standard written, verbal or emailed instructions are administered. The web-based application will assess patient-reported bloating, constipation and dietary adherence leading up to the colonoscopy. Depending on patient responses, additional aperients may be encouraged digitally in the interventional arm with same instructions made available in written format for the control arm. Patient-reported measures will be collected in both arms the day after the procedure using the validated Newcastle ENDOPREM questionnaire. In some sites, participants will undergo digital pre-anaesthetic screening as well. The co-primary endpoints are the adenoma detection rates and patient-reported measures taken after the colonoscopy.

ETHICS AND DISSEMINATION

Ethics approval for this study was obtained from the Western Sydney Local Health District Human Research Ethics Committee (2022/ETH00059). Findings will be reported at national and international gastroenterology meetings and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ACTRN12622000747729.

Efficacy of different bowel preparation regimen volumes for colorectal cancer screening and compliance with European Society of Gastrointestinal Endoscopy performance measures

BACKGROUND

Various volumes of bowel preparation are used in clinical practice. There is conflicting data on the effectiveness of individual regimens. This study aims to evaluate the efficacy and compliance of currently used bowel preparations with the European Society of Gastrointestinal Endoscopy (ESGE) performance measures using data of the Dutch nationwide colorectal cancer screening (CRC) program.

METHODS

In a prospective, multicenter endoscopy database, we identified all CRC screening colonoscopies performed in 15 Dutch endoscopy centers from 2016 to 2020. We excluded procedures without documented bowel preparation or the Boston Bowel Preparation Scale (BBPS) score. Bowel preparation regimens were categorized into three groups, that is, 4-L (polyethylene glycol (PEG)), 2-L (2-L PEG with ascorbic acid) and ≤1-L volumes (sodium picosulfate with magnesium citrate, 1L-PEG with sodium sulfate and ascorbic acid or oral sulfate solution). European Society of Gastrointestinal Endoscopy performance measures included adequate BBPS score (≥6) (>90%), cecal intubation rate (CIR, >90%), adenoma detection rate (ADR, >25%) and polyp detection rate (PDR, >40%). Logistic regression was performed to identify predictive factors for adequate BBPS and patient discomfort.

RESULTS

A total of 39,042 CRC screening colonoscopies were included. Boston Bowel Preparation Scale scores, CIR, ADR and PDR for 4L, 2L and ≤1L regimens all met the minimum ESGE performance measures standards. However, an adequate BBPS score was more frequently seen with 2L regimens (98.0%) as compared to 4L (97.1%) and ≤1L regimens (97.0%) (p < 0.001), respectively. In addition, CIR was higher for ≤1L (98.4%) versus 4L (97.7%) and 2L (97.9%) regimens (p = 0.001), ADR higher for lower volume (≤1L (60.0%) and 2L (61.2)) versus higher volume (4L (58.6%)) regimens (p < 0.001), and PDR higher for ≤1L (70.0%) and 2L (70.8%) versus 4L (67.2%) regimens (p < 0.001). Boston Bowel Preparation Scale for ≤1L regimens was higher when combined with bisacodyl (97.3%) than without (95.6%) (p < 0.001). Overall, bisacodyl use was independently associated with higher patient discomfort (odds ratios = 1.47, confidence intervals = 1.26-1.72).

CONCLUSIONS

Despite variations in bowel preparation volumes, all regimens meet the minimum ESGE performance measures for bowel preparation and other quality parameters. Boston Bowel Preparation Scale can be further improved if ultra low volume regimens are combined with bisacodyl. The choice for either bowel preparation volume can therefore be based on volume-tolerance and patient preference.

Unlocking quality in endoscopic mucosal resection

A review of the development of the key performance metrics of endoscopic mucosal resection (EMR), learning from the experience of the establishment of widespread colonoscopy quality measurements. Potential future performance markers for both colonoscopy and EMR are also evaluated to ensure continued high quality performance is maintained with a focus service framework and predictors of patient outcome.

The Colonoscopy Cookbook: Analysis of effect of a recipe resource on quality and experience of bowel preparation in colonoscopy

Background  High-quality bowel preparation for a colonoscopy improves identification of early lesions in the large bowel, decreases procedure time and increases intervals between colonoscopies. Current recommendations advise a low-residue diet in the days leading up to colonoscopy to improve quality of preparation. This study prepared and provided a recipe resource to patients undergoing colonoscopy and assessed the quality of bowel preparation and patient experience. Patients and methods  A "Colonoscopy Cookbook" resource of recipes that comply with the preoperative diet recommendations was created and added to routine preoperative information given to patients undergoing elective colonoscopies at a regional Australian hospital over a 12-month period. Endoscopic reports were reviewed for each case and quality of bowel preparation was classified as "adequate'' or "inadequate". Data collected were compared to a representative local cohort from 2019. Results  Procedure reports from 96 patients who were provided with the resource were compared with 96 patients who were not. Adequate bowel preparation was nine times as likely when the resource was available (odds ratio 8.54, 95 % confidence interval: 2.85 to 25.60, P  < 0.001) compared to when it was not. The patient experience was assessed using a post-procedure survey, which demonstrated a positive experience in recipe preparation. Most patients would use the resource prior to future colonoscopies. Conclusions  Further randomized controlled trials are required to validate this scoping review. Pre-procedure recipe resources may improve quality of bowel preparation in patients undergoing colonoscopy.

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.

Clean mucosal area detection of gastroenterologists versus artificial intelligence in small bowel capsule endoscopy

Studies comparing the detection of clean mucosal areas in capsule endoscopy (CE) using human judgment versus artificial intelligence (AI) are rare. This study statistically analyzed gastroenterologist judgments and AI results. Three hundred CE video clips (100 patients) were prepared. Five gastroenterologists classified the video clips into 3 groups (≥75% [high], 50%-75% [middle], and < 50% [low]) according to their subjective judgment of cleanliness. Visualization scores were calculated using an AI algorithm based on the predicted visible area, and the 5 gastroenterologists' judgments and AI results were compared. The 5 gastroenterologists evaluated CE clip video quality as "high" in 10.7% to 36.7% and as "low" in 28.7% to 60.3% and 29.7% of cases, respectively. The AI evaluated CE clip video quality as "high" in 27.7% and as "low" in 29.7% of cases. Repeated-measures analysis of variance (ANOVA) revealed significant differences in the 6 evaluation indicators (5 gastroenterologists and 1 AI) (P < .001). Among the 300 judgments, 90 (30%) were consistent with 5 gastroenterologists' judgments, and 82 (91.1%) agreed with the AI judgments. The "high" and "low" judgments of the gastroenterologists and AI agreed in 95.0% and 94.9% of cases, respectively. Bonferroni's multiple comparison test showed no significant difference between 3 gastroenterologists and AI (P = .0961, P = 1.0000, and P = .0676, respectively) but a significant difference between the other 2 with AI (P < .0001). When evaluating CE images for cleanliness, the judgments of 5 gastroenterologists were relatively diverse. The AI produced a relatively universal judgment that was consistent with the gastroenterologists' judgements.

Risk factors for inadequate bowel preparation in patients using high- and low-volume cleansing products

INTRODUCTION

Bowel preparation is crucial for colonoscopy completeness and lesions detection. Today, several cleansing products are equally recommended by guidelines, irrespective of patients' characteristics. Identification of preparation-specific risk factors for inadequate bowel preparation may lead to a personalized prescription of cleansing products to refine patients' tolerance and improve endoscopic outcomes.

METHODS

We prospectively enrolled consecutive outpatients referred for colonoscopy using either a high-volume [HV: 4 l polyethylene glycol (PEG)] or a low-volume (LV: 2 l PEG + bisacodyl) preparation. Day-before regimen or split-dose regimen was used for morning or afternoon colonoscopies, respectively. Univariate and multivariate analyses were conducted to identify risk factors related to inadequate bowel preparation, according to the Boston bowel preparation scale for HV and LV preparations.

RESULTS

We enrolled 2040 patients, of which 1815 were included in the final analysis (average age 60.6 years, 50.2% men). Half of them (52%) used LV preparation. Adequate preparation was achieved by 87.6% without differences between the HV and LV groups (89.2% vs. 86.6%; P = 0.098). The use of day-before regimen and incomplete assumption of PEG were independent predictors of poor visibility for either HV or LV preparation. However, different specific risk factors for HV [diabetes: odds ratio (OR), 3.81; 95% confidence interval (CI), 1.91-7.58; low level of instruction: OR, 1.95; 95% CI, 1.11-3.44; and previous abdominal surgery: OR, 2.27; 95% CI, 1.20-4.30] and for LV (heart disease: OR, 2.06; 95% CI, 1.09-3.88; age > 65 years: OR, 1.51; 95% CI, 1.01-2.27) preparations were identified.

CONCLUSION

Day-before preparation and incomplete assumption of the purgative agents affect bowel visibility irrespective of the preparation volume. LV should be preferred to HV preparations in patients with diabetes, low level of instruction, and previous abdominal surgery, whereas an HV preparation should be preferred in patients with heart disease and in older 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.

Predictive Factors of Adequate Bowel Cleansing for Colonoscopy in the Elderly: A Retrospective Analysis of a Prospective Cohort

Factors affecting the quality of bowel preparation for colonoscopy in the elderly are not fully known, and current guidelines provide no specific recommendations. This study aimed to assess the difference in bowel cleansing in young and elderly patients and evaluate predictors of bowel cleansing in the elderly. We retrospectively reviewed a prospective cohort of 1289 patients performing colonoscopy after a 1-, 2-, or 4-L PEG-based preparation. All 1289 were included in the analysis. Overall, 44.6% of patients were aged ≥65 years. Cleansing success (CS) was achieved in 77.3% and 70.3% of patients aged <65 years and ≥65 years, respectively. At multivariable analysis, split regimen (OR = 2.43, 95% CI = 1.34−4.38; p = 0.003), adequate cleansing at previous colonoscopy (OR = 2.29, 95% CI = 1.14−4.73; p = 0.02), tolerability score (OR = 1.29, 95% CI = 1.16−1.44; p < 0.001), a low-fiber diet for at least 3 days (OR = 2.45, 95% CI = 1.42−4.24; p = 0.001), and colonoscopy within 5 h after the end of preparation (OR = 2.67, 95% CI = 1.28−5.56; p = 0.008) were independently associated with CS in the elderly. Combining a low-fiber diet for at least 3 days, split preparation, and colonoscopy within 5 h allowed a CS rate above 90% and should always be encouraged. A 1-L PEG-ASC preparation was also associated with greater high-quality cleansing of the right colon and may be preferred.

Quality of endoscopic screening for colorectal cancer in Italy: A national survey

BACKGROUND

Colorectal cancer (CRC) is a major healthcare problem all over the world and screening is effective in reducing mortality and increasing survival. Since colonoscopy has a central role in faecal immunochemical test (FIT)-based CRC screening and surveillance, consistent quality measures are essential to ensure quality and outcomes. Nevertheless, screening modalities in clinical practice may differ according to the centers experience and the local availability of instrumentation and devices.

AIMS

to assess the quality of endoscopic screening for CRC and adherence to international guidelines across Gastroenterology Departments in Italy.

METHODS

All members of the Italian Society of Gastroenterology (SIGE) were invited to answer a web-based survey.

RESULTS

Data from 64 hospitals from 17 Italian regions were analyzed. 32/64 (50.0%) were from northern, 12/64 (18.75%) from central and 20/64 (31.25%) from southern Italy. Each center is equipped with a median of 5.0 (3.5-7.0) endoscopists involved in CRC screening, 71.4% of which are gastroenterologists. After a positive FIT, most centers (93.8%) schedule a colonoscopy within 3 months. High-definition video endoscopy is routinely performed in 68.8% and chromoendoscopy in 53.1% of centers. Withdrawal time is ≥6 min in 79.9% and cecal intubation rate is ≥90% in 94.4% of departments. Finally, in 92.7% of centers adenoma detection rate (ADR) overcome the minimum standard of 25%. Analyzing the data by regional areas, a significant higher number of median endoscopic examinations/year (6500 vs 4000 and 3000, respectively, p = 0.024) and of endoscopists per center (6.5 vs 5.0 and 3.5, respectively, p < 0.001) has been registered in the northern compared to central-southern centers.

CONCLUSIONS

Data from this survey show adequacy and good quality of endoscopic screening for CRC in Italy, highlighting, at the same time, relevant deficiencies and a discrepancy in procedural attitudes between the different centers. These findings call for a urgent action to overcome the shortcomings, refine and homogenize the behaviour of all screening centers in the national territory and improve the outcomes.

Prevalence of missed lesions in patients with inadequate bowel preparation through a very early repeat colonoscopy

OBJECTIVES

When bowel preparation (BP) is inadequate, international guidelines recommend repeating the colonoscopy within 1 year to avoid missing clinically relevant lesions. We aimed to determine the rate of missed lesions in patients with inadequate BP through a very early repeat colonoscopy with adequate BP.

METHODS

Post hoc analysis was conducted using data collected from a prospective multicenter randomized clinical trial including patients with inadequate BP and then repeat colonoscopy. Inadequate BP was defined as the Boston Bowel Preparation Scale (BBPS) score <2 points in any segment. We included patients with any indication for colonoscopy. The adenoma detection rate (ADR), advanced ADR (AADR), and serrated polyp detection rate (SPDR) were calculated for index and repeat colonoscopies.

RESULTS

Of the 651 patients with inadequate BP from the original trial, 413 (63.4%) achieved adequate BP on repeat colonoscopy. The median interval between index and repeat colonoscopies was 28 days. On repeat colonoscopy, the ADR was 45.3% (95% confidence interval [CI] 40.5-50.1%), the AADR was 10.9% (95% CI 8.1-14.3%), and the SPDR was 14.3% (95% CI 10.9-17.7%). Cancer was discovered in four patients (1%; 95% CI 0.2-2.5%). A total of 60.2% of all advanced adenoma (AA) were discovered on repeat colonoscopy. A colon segment scored BBPS = 0 had most AA (66.1%) and all four cancers.

CONCLUSION

Patients with inadequate BP present a high rate of AAs on repeat colonoscopy. When a colonoscopy has a colon segment score BBPS = 0, we recommend repeating the colonoscopy as soon as possible.

Oral sulfate solution benefits polyp and adenoma detection during colonoscopy: Meta-analysis of randomized controlled trials

OBJECTIVES

Although oral sulfate solution (OSS) has been revealed to be not only safe and efficacious but also noninferior to polyethylene glycol with ascorbic acid (PEG + ASC), it is unclear whether OSS can ultimately increase the polyp detection rate (PDR) and adenoma detection rate (ADR). We performed this meta-analysis to estimate the effect of OSS on PDR and ADR during colonoscopy.

METHODS

We searched PubMed, EMBASE, and the Cochrane Library to identify relevant randomized controlled trials (RCTs) investigating the comparative effect of OSS versus PEG + ASC on the PDR and ADR during colonoscopy. Cecal intubation time (CIT), cecal intubation rate (CIR), and bowel preparation score were also evaluated. Review Manager (RevMan) version 5.3.0 was used to perform statistical analysis.

RESULTS

Eight RCTs involving 2059 patients fulfilled the selection criteria. Meta-analysis suggested that OSS significantly increased the PDR (47.34% vs. 40.14%, risk ratio [RR] 1.13, 95% confidence interval [CI] 1.03-1.24, P = 0.01) and ADR (44.60% vs. 38.14%, RR 1.17, 95% CI 1.03-1.33, P = 0.01) during colonoscopy. Subgroup analysis showed that the beneficial effects of OSS on PDR and ADR were consistent among patients with mean age >55 years and with body mass index <25 kg/m² receiving outpatient colonoscopy, morning colonoscopy, and the 2-L bowel preparation protocol. Meanwhile, patients receiving OSS had a beneficial bowel preparation score.

CONCLUSION

Compared with polyethylene glycol-based regimens, the OSS bowel preparation regimen significantly increased the PDR and ADR in patients undergoing colonoscopy.

A prospective cohort study of the relationship between the withdrawal time and the detection rate of colorectal adenoma

BACKGROUND AND AIMS

The effect of colonoscopy withdrawal time (WT) beyond 6 min on colorectal adenoma detection rate (ADR) is unclear. We focused on the relationship between WT and ADR.

MATERIALS AND METHODS

This study was a prospective observational study involving 437 patients who underwent colonoscopy at Tongren Hospital in Shanghai from 1 July 2020 to 31 August 2020. Patients were divided into two groups according to whether the WT was >6 min. Age, sex, body mass index (BMI), defoaming rate score, Boston bowel preparation scale (BBPS), primary colonoscopy, hypertension, diabetes mellitus, dietary preparation 1 day before the examination, and abdominal surgery history factors were analysed by univariate and multivariable logistic regression to explore the odds ratios (ORs) of ADR in two WT groups. Restricted cubic spline regression was used to further analyze the relationship between WT and the ORs of adenoma detection.

RESULTS

The ADR among 437 patients was 17.16% (75/437). Multivariable regression analysis showed that in the group with WT >6 min, patients aged ≥50 years old and male could have an increased risk of adenoma detection (OR 5.80, 95% CI 2.32-14.47; p < .001; OR 2.30, 95% CI 1.19-4.43; p = .013). The cubic spline curve showed that the ADR increased with time for WT of 6-8 min, and the highest ADR was achieved when the WT was controlled at 8 min (WT = 5.997, OR = 0.997; WT = 8.240 min, OR = 3.092).

CONCLUSION

The highest ADR was achieved when the WT of colonoscopy was controlled at 8 min.

High-Volume Colonic Lavage Is a Safe and Preferred Colonoscopy Preparation for Patients With Inflammatory Bowel Disease

Background

Colonoscopies provide a crucial diagnostic and surveillance tool for inflammatory bowel disease (IBD). Accordingly, IBD patients undergo repeated and frequent colonoscopies. The oral purgative bowel prep (BP) is often burdensome on patients, resulting in delayed or missed colonoscopies due to patient noncompliance. Additionally, oral BP has been noted to possibly induce colon mucosal inflammatory changes in some patients, which may be misleading when assessing actual disease activity.

Methods

In this retrospective clinical study, we evaluated the use of an FDA cleared, defecation-inducing high-volume colon irrigation (>40 L) BP to prepare IBD patients for colonoscopy. Data were collected at 4 US Hygieacare centers from September 2016 to March 2021. The IBD patient population consisted of 314 patients that underwent 343 BPs. The BPs were prescribed by 65 physicians and performed by 16 nurses and technicians.

Results

Patient ages were 20-85 years old, 76% females, 24% males, and 97% of the patients were adequately prepared for their colonoscopy (n = 309). Patient satisfaction with the BP was very high, as reflected in postprocedure surveys and open-ended responses text analyses, and there were no serious adverse events.

Conclusions

We present data supporting that the defecation-inducing high-volume colon irrigation BP for colonoscopy is safe, effective, and preferred for IBD patients. Using this BP for IBD patients can allow earlier interventions, significantly impacting disease management and future outcomes.

The Efficacy of Senna Bowel Preparation for Colonoscopy: A Systematic Review and Meta-analysis

The quality of bowel preparation is an extremely important determinant of colonoscopy results. However, the efficacy of senna regimens in improving bowel cleanliness is uncertain. We conducted a systematic review and meta-analysis to synthesize data on whether using a senna bowel preparation regimen enhances the bowel cleanliness. We searched Web of Science Core Collection, MEDLINE, PubMed, Embase, Cochrane Library, and Scopus databases (from the inception to August 2021). The primary efficacy outcome was bowel cleanliness. Secondary outcomes included patient compliance, tolerance, and adverse events. Eleven trials fulfilled the inclusion criteria (3,343 patients. Overall, we found no significant differences in bowel cleanliness between the senna regimen and other bowel preparation regimens (odds ratio [95% confidence interval]: 1.02 [0.63, 1.67], p = 0.93). There was significant difference in tolerance (odds ratio [95% confidence interval]: 1.66 [1.08, 2.54], p = .02) and compliance (odds ratio [95% confidence interval]: 3.05 [1.42, 6.55], p = .004). The senna regimen yielded a significantly greater proportion of no nausea (odds ratio [95% confidence interval]: 1.84 [1.45, 2.32]) and vomiting (odds ratio [95% confidence interval]: 1.65 [0.81, 3.35]). Compared with other bowel preparation regimens, the senna regimen may be effective and safe in bowel cleaning before colonoscopy, with superior compliance and tolerance.

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.

Predictive factors of inadequate bowel preparation for elective colonoscopy

Aim

This study aimed to evaluate the effects of factors like demographic items, comorbidities, and drug history on the inadequacy of colonic preparation before colonoscopy.

Background

Inadequate bowel preparation can lead to lower polyp detection rates, longer procedure times, and lower cecal intubation rates.

Methods

This population-based study was conducted on 2476 Iranian adults who were referred to two tertiary centers for elective colonoscopy between 2017 and 2018. Bowel preparation quality was scored by the Boston bowel preparation scale (BBPS). Univariate and multivariate logistic regressions were used to find the independent predictors of bowel preparation inadequacy.

Results

The results showed that 31.8% of patients had inadequate bowel preparation before their colonoscopy. Higher age, BMI>25, abdominal circumference>95 cm, low fruit consumption, and history of smoking were independently correlated with bowel preparation inadequacy. Additionally, using NSAIDs and SSRIs were correlated with bowel preparation adequacy in multivariate regression analysis. Finally, age, gender, ethnicity, BMI, abdominal circumference, fruit consumption, smoking, NSAIDs, SSRIs, education, constipation, physical activity, and diabetes entered the predictive model of this study. The area under the curve (AUC) reached 0.70 in the final step.

Conclusion

The independent risk factors associated with colonic preparation inadequacy were identified, and herein, a predictive model is suggested for identifying patients with a high risk of bowel preparation inadequacy before a colonoscopy so that alternative preparation techniques can be employed among high-risk groups to yield optimal preparation quality.

Can image-enhanced endoscopy improve adenoma detection rate?

An accumulating body of evidence has shown that detection and resection of pre-cancerous adenoma by colonoscopy could effectively prevent colorectal cancer (CRC) and its related mortality. Among various colonoscopy quality indicators, such as cecal intubation rate, withdrawal time, and adenoma detection rate (ADR); ADR is the most important and most closely associated with the subsequent risk of CRC. Image-enhanced endoscopy (IEE), including digital and dye-based IEE, was originally developed to discriminate neoplastic from non-neoplastic lesions but later studies have demonstrated that it can also enhance lesion detection by enhancing the contrast between the lesion and background colonic mucosa. Nevertheless, using IEE in colonoscopy for lesion detection is still not the standard way of practice in the real world. For a better understanding of current IEE modalities, this review introduces and compares the currently available IEE modalities and their efficacy in detecting adenoma from the results of randomized controlled trials or meta-analyses.

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

BACKGROUND

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Novel frontiers of agents for bowel cleansing for colonoscopy

The incidence of colorectal cancer (CRC) is characterized by rapid declines in the wake of widespread screening. Colonoscopy is the gold standard for CRC screening, but its accuracy is related to high quality of bowel preparation (BP). In this review, we aimed to summarized the current strategy to increase bowel cleansing before colonoscopy. Newly bowel cleansing agents were developed with the same efficacy of previous agent but requiring less amount of liquid to improve patients’ acceptability. The role of the diet before colonoscopy was also changed, as well the contribution of educational intervention and the use of adjunctive drugs to improve patients’ tolerance and/or quality of BP. The review also described BP in special situations, as lower gastrointestinal bleeding, elderly people, patients with chronic kidney disease, patients with inflammatory bowel disease, patients with congestive heart failure, inpatient, patient with previous bowel resection, pregnant/lactating patients. The review underlined the quality of BP should be described using a validate scale in colonoscopy report and it explored the available scales. Finally, the review explored the possible contribution of bowel cleansing in post-colonoscopy syndrome that can be related by a transient alteration of gut microbiota. Moreover, the study underlined several points needed to further investigations.

Updates, Controversies, and Emerging Approaches in Colorectal Screening

Colorectal cancer (CRC) is the third most common cancer worldwide and the second leading cause of cancer-related deaths. Despite the threatening statistics, the US burden for CRC has been decreasing, which is likely multifactorial and has partial contribution from widespread timely screening, more advanced CRC treatment, and daily aspirin use in some patients. While overall death rate from CRC decreased by approximately a half between 1975 and 2012, epidemiologic studies demonstrate that CRC incidence is increasing in the younger population. This pattern has prompted the American Cancer Society (ACS) to revise their guidelines. In this review, we plan to discuss the most recent changes in guidelines, data to support them, controversies concerning CRC screening methods, age to start and to stop screening, and post-colonoscopy/polypectomy surveillance guidelines.

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

Background

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

Aims

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

Methods

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

Results

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

Conclusions

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

Is it time we split bowel preparation for all colonoscopies? Outcomes from a national survey of bowel preparation practice in the UK

Introduction

Adequate bowel preparation is a prerequisite for effective colonoscopy. Split bowel preparation results in optimal cleansing. This study assessed the bowel preparation regimes advised by endoscopy units across the UK, and correlated the differences with outcomes.

Methods

Trusts in the UK were surveyed, with data requested between January 2018 and January 2019, including: the type and timing of preparation, pre-endoscopy diet, adequacy rates and polyp detection. Trusts were grouped according to the timing of bowel preparation. χ² test was used to assess for differences in bowel preparation adequacy.

Results

Moviprep was the first line bowel preparation in 79% of trusts. Only 7% of trusts advised splitting bowel preparation for all procedures, however, 91% used split bowel preparation for afternoon procedures. Trusts that split preparation for all procedures had an inadequacy rate of 6.7%, compared with 8.5% (p<0.001) for those that split preparation for PM procedures alone and 9.5% (p<0.001) for those that provided day before preparation for all procedures. Morning procedures with day-before preparation had a higher rate of inadequate cleansing than afternoon procedures that received split preparation (7.7% vs 6.5 %, p<0.001). The polyp detection rate for procedures with adequate preparation was 37.1%, compared with 26.4% for those that were inadequate.

Conclusion

Most trusts in the UK do not provide instructions optimising the timing of bowel preparation prior to colonoscopy. This correlated with an increased rate of inadequate cleansing. Splitting bowel preparation is likely to reduce the impacts of poor cleansing: missed lesions, repeat colonoscopies and significant costs.

Novel 1-L polyethylene glycol + ascorbate versus high-volume polyethylene glycol regimen for colonoscopy cleansing: a multicenter, randomized, phase IV study

BACKGROUND AND AIMS

Adequate bowel cleansing is critical to ensure quality and safety of a colonoscopy. A novel 1-L polyethylene glycol plus ascorbate (1L-PEG+ASC) regimen was previously validated against low-volume regimens but was never compared with high-volume regimens.

METHODS

In a phase IV study, patients undergoing colonoscopy were randomized 1:1 to receive split-dose 1L PEG+ASC or a split-dose 4-L PEG-based regimen (4L-PEG) in 5 Italian centers. Preparation was assessed with the Boston Bowel Preparation Scale (BBPS) by local endoscopists and centralized reading, both blinded to the randomization arm. The primary endpoint was noninferiority of 1L-PEG+ASC in colon cleansing. Secondary endpoints were superiority of 1L-PEG+ASC, patient compliance, segmental colon cleansing, adenoma detection rate, tolerability, and safety.

RESULTS

Three hundred eighty-eight patients (median age, 59.8 years) were randomized between January 2019 and October 2019: 195 to 1L-PEG+ASC and 193 to 4L-PEG. Noninferiority of 1L-PEG+ASC was demonstrated for cleansing in both the entire colon (BBPS ≥ 6: 97.9% vs 93%; relative risk [RR], 1.03; 95% confidence interval [CI], 1.001-1.04; P superiority = .027) and in the right-sided colon segment (98.4% vs 96.0%; RR, 1.02; 95% CI, .99-1.02; P noninferiority = .013). Compliance was higher with 1L-PEG+ASC than with 4L-PEG (178/192 [92.7%] vs 154/190 patients [81.1%]; RR, 1.10; 95% CI, 1.05-1.12), whereas no difference was found regarding safety (moderate/severe side effects: 20.8% vs 25.8%; P = .253). No difference in adenoma detection rate (38.8% vs 43.0%) was found.

CONCLUSIONS

One-liter PEG+ASC showed noninferiority compared with 4L-PEG in achieving adequate colon cleansing and provided a higher patient compliance. No differences in tolerability and safety were detected. (Clinical trial registration number: NCT03742232.).

Clinical practice standards for colonoscopy

Colonoscopy is considered as the most effective tool for preventing, screening, and diagnosing colorectal lesions. Effectiveness of colonoscopy was identified as a major priority, and it strictly depends on quality measures. Therefore, international guidelines were formulated on quality indicators for colonoscopy, aiming to reduce the rate of interval cancers related to missed lesions during colonoscopy. Quality indicators are divided into 3 time periods: preprocedure, intraprocedure, and postprocedure.  The main pre-procedural indicators are the assessment of the appropriateness of indication of colonoscopy and the prescription of adequate bowel preparation during a consultation prior to colonoscopy. Per-procedural criteria include all technical aspects of the procedure, which are "endoscopist-dependent" factors, particularly cecal intubation, detection of adenomas and withdrawal time. The main post-procedure indicators are the rate of complications, patient experience and optimal surveillance intervals following removal of colorectal polyps. The implementation of key performance measures in endoscopy practice is increasingly important as it can help improving our care of patients and optimize outcomes. In this review, the "Club d'endoscopie digestive" (CED) presented a summary of the main colonoscopy quality indicators, and suggested recommendations that took into account the particularities of our local conditions.

Thoughts on factors related to colonoscopy quality

With the increase in health consciousness and the prevalence of early gastrointestinal cancer screening, the number of diagnosed cases of colorectal polyps and adenomas in the Chinese general population has substantially increased. However, the overall adenoma detection rate (ADR) in China remains lower than the global standard of 30%. High quality colonoscopy is pivotal for increasing the ADR and reducing the risk of interval colon cancer. A few factors are related to the quality of colonoscopy, including preoperative evaluation of examinees, bowel preparation, techniques for intubation, use of image enhancement endoscopy, withdraw time, and prevention of adverse events.

Evaluating key characteristics of ideal colorectal cancer screening modalities: the microsimulation approach

BACKGROUND AND AIMS

Screening for colorectal cancer (CRC) can effectively reduce CRC incidence and mortality. Besides colonoscopy, tests for the detection of biomarkers in stool, blood, or serum, including the fecal immunochemical test (FIT), ColoGuard, Epi proColon, and PolypDx, have recently been advanced. We aimed to identify the characteristics of theoretic, highly efficient screening tests and calculated the effectiveness and cost effectiveness of available screening tests.

METHODS

Using the microsimulation-based colon modeling open-source tool (CMOST), we simulated 142,501 theoretic screening tests with variable assumptions for adenoma and carcinoma sensitivity, specificity, test frequency, and adherence, and we identified highly efficient tests outperforming colonoscopy. For available screening tests, we simulated 10 replicates of a virtual population of 2 million individuals, using epidemiologic characteristics and costs assumptions of the United States.

RESULTS

Highly efficient theoretic screening tests were characterized by high sensitivity for advanced adenoma and carcinoma and high patient adherence. All simulated available screening tests were effective at 100% adherence to screening and at expected real-world adherence rates. All tests were cost effective below the threshold of 100,000 U.S. dollars per life year gained. With perfect adherence, FIT was the most effective and cost-efficient intervention, whereas Epi proColon was the most effective at expected real-world adherence rates. In our sensitivity analysis, assumptions for patient adherence had the strongest impact on effectiveness of screening.

CONCLUSIONS

Our microsimulation study identified characteristics of highly efficient theoretic screening tests and confirmed the effectiveness and cost-effectiveness of colonoscopy and available urine-, blood-, and stool-based tests. Better patient adherence results in superior effectiveness for CRC prevention in the whole population.

Do Water-aided Techniques Improve Serrated Polyp Detection Rate During Colonoscopy?: A Systematic Review With Meta-Analysis

BACKGROUND AND STUDY AIMS

The utility of water-aided techniques (WT): water exchange (WE) and water immersion (WI) have been studied extensively in the literature for improving colonoscopy outcome metrics such as adenoma detection rate. Serrated polyps owing to their location and appearance have a high miss rate. The authors performed a systematic review and meta-analysis of studies comparing WT with the standard gas-assisted (GA) method to determine if there was any impact on serrated polyp detection rate (SPDR) and sessile serrated polyp detection rate.

METHODS

The following databases were queried for this systematic review: Medline, EMBASE, Cochrane Library, CINAHL, and Web of Sciences. The authors only included randomized controlled trials (RCTs). The primary outcome was SPDR and secondary outcomes were sessile serrated polyp detection rate and cecal intubation rate. Risk ratios (RRs) were calculated for each outcome. A P-value <0.05 was considered to be statistically significant.

RESULTS

A total of 4 RCTs (5 arms) with 5306 patients (2571 in the GA group and 2735 in the WT group) were included. The SPDR was significantly increased for the WT group compared with GA (6.1% vs. 3.8%; RR, 1.63; 95% confidence interval, 1.24-2.13; P<0.001; I2=22.7%). A subgroup analysis for WE technique also demonstrated improved SPDR compared with the GA method (4.9% vs. 3.2%; RR, 1.57; 95% confidence interval, 1.15-2.14; P=0.004; I2=6.1%).

CONCLUSIONS

WT, particularly, the WE method results in improved SPDR. This technique should be encouraged in a clinical setting to detect these polyps to prevent interval colorectal cancer.

Risk Factors of Inadequate Bowel Preparation for Screening Colonoscopy

The success of a colonoscopy in detecting and removing pre-cancerous and cancerous lesions depends heavily on the quality of bowel preparation. Despite efforts, 20–44% of colonoscopy participants have an inadequate bowel preparation. We aimed to assess and compare risk factors for inadequate bowel preparation and for the presence of advanced colorectal neoplasms in routine screening practice. In this cross-sectional study, among 8125 participants of screening colonoscopy in Germany with a comprehensive assessment of sociodemographic factors, lifestyle and medical history, we examined factors associated with inadequate bowel preparation and with findings of advanced neoplasms using adjusted log-binomial regression models. Among the identified risk factors assessed, three factors were identified that were significantly associated with inadequate bowel preparation: age ≥ 70 years (adjusted prevalence ratios, aPR, 1.50 95%CI 1.31–1.71), smoking (aPR 1.29 95%CI 1.11–1.50) and abdominal symptoms (aPR 1.14 95%CI 1.02–1.27). The same risk factors were also associated with the prevalence of advanced neoplasms in our study (aPR 1.72, 1.62 and 1.44, respectively). The risk factors associated with inadequate bowel preparation in this study were also associated with a higher risk for advanced neoplasms. Inadequate bowel preparation for colonoscopy might lead to missed colorectal cancer (CRC) precursors and the late diagnosis of CRC. People at high risk of advanced neoplasms are in particular need of enhanced bowel preparation.

Impact of Inadequate Bowel Cleansing on Colonoscopic Findings in Routine Screening Practice

INTRODUCTION

Colonoscopy is an imperfect gold standard for detecting colorectal neoplasms because some proportion of adenomas may be missed, mainly small lesions. This proportion is expected to be higher in case of inadequate bowel cleansing, which is frequently seen in routine practice. We estimated the proportions of neoplasms that are in principle detectable by colonoscopy but might be missed in case of incomplete bowel preparation.

METHODS

For 8,193 participants of screening colonoscopy in South-Western Germany, recruited between 2005 and 2016, the prevalence and numbers of different findings were extracted from colonoscopy reports and compared according to the reported bowel preparation quality.

RESULTS

Bowel preparation quality was reported as good, poor, or was unspecified in 30.3%, 11.1%, and 58.6% of colonoscopy records. Reported prevalences of nonadvanced adenomas (NAAs) were similar among participants with poor and unspecified bowel preparation quality but substantially lower than among participants with good bowel preparation (adjusted prevalence rate ratio [RR] 0.86, 95% confidence interval [CI]: 0.77-0.96). The differences were observed for proximal but not for distal NAAs (RRs 0.82, 95% CI: 0.71-0.95 and 0.95, 95% CI: 0.82-1.10).

DISCUSSION

Our study suggests that a significant proportion of NAAs located in the proximal colon might be missed during colonoscopy if bowel cleansing is not adequate. Major efforts should be made to further facilitate and enhance high-quality bowel preparation in routine screening practice.

Quality Improvement of Bowel Preparation for Screening Colonoscopies: A Study of Hospital Team Resource Management in Taiwan

BACKGROUND AND OBJECTIVES

This study aimed to investigate the impact of patient education using a medical team resource management (TRM) method on the adequacy of bowel preparation.

METHODS

The study setting was a single hospital in northern Taiwan, and a total of 2104 (884 female, 1220 male) healthy subjects who underwent a health checkup colonoscopy screening were enrolled before and after the application of the TRM program intervention. The efficacy of the TRM intervention and the factors affecting bowel preparation were estimated using multivariate logistic regression.

RESULTS

The prevalence of adequate bowel preparation improved significantly from the preintervention period to the postintervention and validation periods, which had prevalence of 79.0%, 81.3%, and 84.0%, respectively. Using the preintervention period prevalence as a reference, the adjusted odds ratios (aORs) for adequate bowel preparation in the postintervention and validation periods were 2.199 (95% confidence interval [CI]: 1.538-3.142) and 2.035 (1.525-2.716), respectively. Men had a lower probability of adequate cleansing than women (aOR = 0.757; 95% CI = 0.598-0.957), and purgative containing polyethylene glycol had a lower probability of adequate cleansing than purgative containing sodium phosphate (aOR = 0.366; 95% CI: 0.277-0.483).

CONCLUSIONS

Bowel preparation quality for colonoscopy could be improved by enhancing patient education via TRM, and we suggest that effective quality improvement schemes should be proposed for health-screening programs.

Colon Capsule CLEansing Assessment and Report (CC-CLEAR): a new approach for evaluation of the quality of bowel preparation in capsule colonoscopy

BACKGROUND AND AIMS

Current colon capsule (CC) cleansing grading scales rely on subjective parameters and lack proper interobserver agreement. We should strive for higher intra- and interobserver agreement for the evaluation of the cleansing quality of CCs. Here we sought to validate a new grading scale for the evaluation of CC cleansing.

METHODS

For the new grading scale, named Colon Capsule CLEansing Assessment and Report (CC-CLEAR), the colon was divided in 3 segments: right-sided, transverse, and left-sided colon. Each segment was scored according to an estimation of the percentage of visualized mucosa (0, <50%; 1, 50%-75%; 2, >75%; 3, >90%). The overall cleansing classification was a sum of each segment score, grading between excellent (8-9), good (6-7), and inadequate (0-5). Any segment scoring ≤1 resulted in inadequate overall classification. Videos were reviewed and scored using CC-CLEAR and the Leighton-Rex grading scale by 2 experienced operators blinded to each other. Kendall's coefficient evaluated inter- and intraobserver agreement.

RESULTS

We included 58 consecutive CCs, corresponding to 75.9% women, with a mean age of 65 years. Overall cleansing CC-CLEAR classifications were as follows: reader A, 22.4% (n = 13) excellent, 31% (n = 18) good, and 46.5% (n = 27) inadequate; and reader B, 24.1% (n = 14) excellent, 22.4% (n = 13) good, and 53.4% (n = 31) inadequate. CC-CLEAR interobserver agreement was superior to the Leighton-Rex scale (Kendall's W .911 vs .806, respectively; P < .01). The intraobserver agreement for CC-CLEAR was excellent for both readers (P > .01).

CONCLUSIONS

CC-CLEAR is a new practical and reliable grading scale for the evaluation of bowel preparation quality using a CC, with excellent inter- and intraobserver agreement.

Efficacy, tolerability and safety of a split-dose bowel cleansing regimen of magnesium citrate with sodium picosulfate - a phase IV clinical observational study

BACKGROUND

There are contradictory results about the effect of magnesium citrate plus sodium picosulfate bowel cleansing agents on the fluid and electrolyte balance. Therefore, this study aimed to determine the efficacy, tolerability and safety of this medication in colonoscopy preparation.

METHODS

233 patients were enrolled in this phase IV prospective observational study. The effectiveness of bowel cleansing was assessed using the Boston Bowel Preparation Scale (BBPS). Adequate cleansing was defined as BBPS ≥ 6 and excellent cleansing as BBPS > 7. Tolerability was examined using a standardized questionnaire. In the safety analysis, the change of serum electrolytes levels and renal function during bowel cleansing was assessed.

RESULTS

Adequate and excellent bowel cleansing were achieved 94.85% and 72.96% of cases, respectively. None or very mild symptoms were reported in 47.21% of cases. Statistically significant changes occurred in serum potassium (4.38±0.43 vs. 4.25±0.43 mmol/L, p<0.0001), urea (4.86±1.37 vs. 3.84±1.43 mmol/L, p<0.0001) and creatinine (male: 81.07±16.02 vs. 84.54±15.11 μmol/L; female: 69.32±12.22 vs. 72.96±12.11 μmol/L, p<0.0001) levels during the colonoscopy preparation. However, the number of patients with values outside of the normal range increased significantly only in the case of serum urea (3.95% vs. 26.97%, p<0.0001).

CONCLUSION

Magnesium citrate with sodium picosulfate is outstandingly effective, well tolerated and a safe agent in colonoscopy preparation. It caused significant, but non-clinically relevant changes in serum electrolytes levels and renal function.

The impact of deep convolutional neural network-based artificial intelligence on colonoscopy outcomes: A systematic review with meta-analysis

BACKGROUND AND AIM

The utility of artificial intelligence (AI) in colonoscopy has gained popularity in current times. Recent trials have evaluated the efficacy of deep convolutional neural network (DCNN)-based AI system in colonoscopy for improving adenoma detection rate (ADR) and polyp detection rate (PDR). We performed a systematic review and meta-analysis of the available studies to assess the impact of DCNN-based AI-assisted colonoscopy in improving the ADR and PDR.

METHODS

We queried the following database for this study: PubMed, Embase, Cochrane Library, Web of Sciences, and Computers and Applied Sciences. We only included randomized controlled trials that compared AI colonoscopy to standard colonoscopy (SC). Our outcomes included ADR and PDR. Risk ratios (RR) with 95% confidence interval (CI) were calculated using random effects model and DerSimonian-Laird approach for each outcome.

RESULTS

A total of three studies with 2815 patients (1415 in SC group and 1400 in AI group) were included. AI colonoscopy resulted in significantly improved ADR (32.9% vs 20.8%, RR: 1.58, 95% CI 1.39-1.80, P = < 0.001) and PDR (43.0% vs 27.8%, RR: 1.55, 95% CI 1.39-1.72, P = < 0.001) compared with SC.

CONCLUSION

Given the results and limitations, the utility of AI colonoscopy holds promise and should be evaluated in more randomized controlled trials across different population, especially in patients solely undergoing colonoscopy for screening purpose as improved ADR will ultimately help in reducing incident colorectal cancer.

Randomized Controlled Trial of Polyethylene Glycol versus Oral Sodium Phosphate for Bowel Preparation in Unsedated Colonoscopy

Aim

To identify the most effective laxative for bowel preparation in unsedated colonoscopy.

Methods

Between April 2019 and April 2020, a total of 586 outpatients scheduled for unsedated colonoscopy at the First Hospital of Jilin University (Changchun, China) were randomized into one of two groups, namely, the polyethylene glycol (PEG) group or the oral sodium phosphate solution (OSP) group. The cleaning efficiency and other relevant clinical parameters were compared between the two groups.

Results

Each group consisted of 293 patients. There were no significant differences in gender, body mass index, and history of abdominal surgery between the two groups. There were more cases of laxative intolerance in the PEG group than in the OSP group (7.5% vs. 0.7%, P < 0.05). After tube insertion, we found that the cleaning efficiency of OSP was better than that of PEG (P < 0.05). After cleaning, there was no significant difference in bowel cleanliness between the two groups (P > 0.05). The colonoscopic insertion time of the PEG group was significantly shorter than that of the OSP group (10.0 vs. 12.0 min, P = 0.002), and colonoscopic insertion was more difficult in the OSP group than in the PEG group (P = 0.036). The VAS score of the PEG group patients was significantly lower than that of OSP group patients (4.0 ± 1.3 vs. 5.2 ± 1.7, P ≤ 0.001). There were no significant differences in the cecal intubation rate and the detection rate of polyps and ulcers/erosion between the two groups.

Conclusion

The cleaning efficiency and tolerability of OSP were preferable to those of PEG, but there was no significant difference in bowel cleanliness after washing the colon and suctioning the fluid. Compared with patients of the OSP group, those of the PEG group required a shorter colonoscopic insertion time and reported a more comfortable experience. Therefore, for cases that are tolerant of PEG, PEG is a better choice for unsedated colonoscopy.

New Ultra Low Volume Bowel Preparation and Overview of Existing Bowel Preparations

BACKGROUND

Adequate bowel cleansing is essential in achieving a good quality colonoscopy. However, one of the barriers to achieving high-quality bowel cleansing is the patient's tolerability. Different bowel preparations have been developed to improve tolerability while maintaining adequate bowel cleansing.

OBJECTIVES

We aim to explore the pros and cons of commonly used bowel preparations, particularly highlighting the new ultra-low volume bowel preparation.

METHODS

Extensive literature search was carried out on various databases to evaluate the effectiveness and side effects of different bowel cleansing agents, including findings of recent clinical trials on ultra-low bowel preparation.

RESULTS

Polyethylene glycol (PEG) has been commonly used as a bowel prep. Due to its high volume required to ingest to achieve an adequate effect, it has been combined with various adjuncts to reduce the volume to make it more tolerable. Magnesium and phosphate-based preps can achieve low volume, but they can be associated with multiple side effects, mainly electrolyte disturbances. Ultra low volume prep (NER1006) was achieved by combing PEG with ascorbic acid, and its efficacy and side effects were demonstrated in three noninferiority studies.

CONCLUSION

It is important to consider patient preferences, co-morbidities and tolerability, and efficacy and side effect profiles when choosing bowel prep for patients undergoing colonoscopy. New ultra-low bowel prep showed promising results in initial clinical trials, but further real-world post-marketing data will inform its value in clinical practice.

Effectiveness and safety of NER1006 versus standard bowel preparations: A meta-analysis of randomized phase-3 clinical trials

BACKGROUND

A 1 L PEG-based preparation for colonoscopy (NER1006) has been recently developed.

AIMS

We conducted a meta-analysis of randomized controlled trials (RCTs) to explore the effectiveness and safety of NER1006 versus traditional preparations.

METHODS

PubMed/Medline and Embase were systematically searched through January 2020 for phase-3 RCTs comparing NER1006 versus standard preparations.

RESULTS

Three RCTs (1879 participants) met the inclusion criteria and were included. The analysis showed a higher cleansing success for NER1006 compared standard preparations (OR=1.28; 95% CI 1.00-1.62; p = 0.047, I²=0%) as well as a greater high-quality cleansing of the right colon (OR=2.13; 95% CI 1.16-3.94; p = 0.015, I²=76.0%) when assessed by the Harefield Cleansing Scale (HCS). The pooled estimate of the NER1006 effect on ADR showed a higher, although not significant, ADR of the right colon (OR=1.19; 95% CI 0.73-1.92; p = 0.485, I²=53%). When considering the impact of NER1006 on mild to moderate treatment-emergent adverse events (TEAEs), we observed a significant pooled estimate of TEAEs (OR=2.31; 95% CI 1.82-2.94; p<0.001, I²=0%).

CONCLUSIONS

When compared to traditional preparations, NER1006 showed a better overall cleansing of the colon as well as a greater high-quality cleansing of the right colon, with comparable ADR. A higher incidence of mild to moderate TEAEs was observed for NER1006, in the absence of serious adverse events.

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

Aims

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

Methods and Results

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

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

Conclusions

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

Efficacy and Tolerability of High- vs Low-Volume Split-Dose Bowel Cleansing Regimens for Colonoscopy: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Efficacy of bowel preparation is an important determinant of outcomes of colonoscopy. It is not clear whether approved low-volume polyethylene glycol (PEG) and non-PEG regimens are as effective as high-volume PEG regimens when taken in a split dose.

METHODS

In a systematic review of multiple electronic databases through January 31, 2019 with a registered protocol (PROSPERO: CRD42019128067), we identified randomized controlled trials that compared low- vs high-volume bowel cleansing regimens, administered in a split dose, for colonoscopy. The primary efficacy outcome was rate of adequate bowel cleansing, and the secondary efficacy outcome was adenoma detection rate. Primary tolerability outcomes were compliance, tolerability, and willingness to repeat. We calculated relative risk (RR) and 95% CI values and assessed heterogeneity among studies by using the I² statistic. The overall quality of evidence was assessed using the GRADE framework.

RESULTS

In an analysis of data from 17 randomized controlled trials, comprising 7528 patients, we found no significant differences in adequacy of bowel cleansing between the low- vs high-volume split-dose regimens (86.1% vs 87.4%; RR, 1.00; 95% CI, 0.98-1.02) and there was minimal heterogeneity (I² = 17%). There was no significant difference in adenoma detection rate (RR, 0.96; 95% CI, 0.87-1.08) among 4 randomized controlled trials. Compared with high-volume, split-dose regimens, low-volume split-dose regimens had higher odds for compliance or completion (RR, 1.06; 95% CI, 1.02-1.10), tolerability (RR, 1.39; 95% CI, 1.12-1.74), and willingness to repeat bowel preparation (RR, 1.41; 95% CI, 1.20-1.66). The overall quality of evidence was moderate.

CONCLUSIONS

Based on a systematic review of 17 randomized controlled trials, low-volume, split-dose regimens appear to be as effective as high-volume, split-dose regimens in bowel cleansing and are better tolerated, with superior compliance.

Determination of the Effectiveness of Informing With the Guidance of an Education Booklet in Patients Undergoing Colonoscopy-A Randomized Controlled Trial

PURPOSE

The aim of this study was to determine the effect of precolonoscopy information with the guidance of an education booklet on anxiety and bowel preparation adequacy in patients undergoing colonoscopy.

DESIGN

A randomized controlled study.

METHODS

The education group was informed face to face by the researcher with the guidance of the colonoscopy education booklet and provided the education booklet. The control group received usual care.

FINDINGS

The mean state and trait anxiety scores of the patients in the education group were found to be significantly lower than the control group. In the education group, the bowel preparation adequacy was determined to be higher compared with the control group.

CONCLUSIONS

Informing patients with the guidance of the education booklet before the colonoscopy decreased patients' state and trait anxiety levels and increased their bowel preparation adequacy.

Effectiveness of very low-volume preparation for colonoscopy: A prospective, multicenter observational study

BACKGROUND

The effectiveness of colonoscopy strictly depends on adequate bowel cleansing. Recently, a 1 L polyethylene glycol plus ascorbate (PEG-ASC) solution (Plenvu; Norgine, Harefield, United Kingdom) has been introduced on the evidence of three phase-3 randomized controlled trials, but it had never been tested in the real-life.

AIM

To assess the effectiveness and tolerability of the 1 L preparation compared to 4 L and 2 L- PEG solutions in a real-life setting.

METHODS

All patients undergoing a screening or diagnostic colonoscopy after a 4, 2 or 1 L PEG preparation, were consecutively enrolled in 5 Italian centers from September 2018 to February 2019. The primary endpoints of the study were the assessment of bowel cleansing success and high-quality cleansing of the right colon. The secondary endpoints were the evaluation of tolerability, adherence and safety of the different bowel preparations. Bowel cleansing was assessed through the Boston Bowel Preparation Scale. Adherence was defined as consumption of at least 75% of each dose, while tolerability was evaluated through a semi-quantitative scale. Safety was systematically monitored through adverse events reporting.

RESULTS

Overall, 1289 met the inclusion criteria and were enrolled in the study. Of these, 490 patients performed a 4 L-PEG preparation (Selgesse^®), 566 a 2 L-PEG cleansing (Moviprep^® or Clensia^®) and 233 a 1 L-PEG preparation (Plenvu^®). Bowel cleansing by Boston Bowel Preparation Scale was 6.5 ± 1.5 overall and 6.3 ± 1.5, 6.2 ± 1.5, 7.3 ± 1.5 (P < 0.001) in the subgroups of 4 L, 2 L and 1 L-PEG preparation, respectively. Cleansing success was achieved in 72.4%, 74.1% and 90.1% (P < 0.001), while a high-quality cleansing of the right colon in 15.9%, 12.0% and 41.4% (P < 0.001) for 4 L, 2 L and 1 L-PEG preparation groups, respectively. The 1 L preparation was the most tolerated compared to the 2 and 4 L-PEG solutions in the absence of serious adverse events within any of the three groups. Multiple regression models confirmed 1 L PEG-ASC preparation as an independent predictor of overall cleansing success, high-quality cleansing of the right colon and of tolerability.

CONCLUSION

This study supports the effectiveness and tolerability of 1 L PEG-ASC, also showing it is an independent predictor of overall cleansing success, high-quality cleansing of the right colon and of tolerability.