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

Impact of Bowel Cleansing on Polyp and Adenoma Detection Rate: Post-Hoc Analysis of a Randomized Clinical Trial

OBJECTIVES

To assess the impact of bowel cleansing quality on polyp detection rate (PDR) and adenoma detection rate (ADR) and explore predictors of lesion detection rate in patients undergoing colonoscopy.

METHODS

This is a post-hoc analysis of a multicenter randomized controlled trial (RCT) comparing 1L polyethylene glycol plus ascorbate (1L PEG+ASC) vs. 4L PEG as bowel preparation for colonoscopy.

RESULTS

PDR was significantly higher (35.6% vs. 18.5%, p = 0.013), and ADR was higher even if not significantly (25.6% vs. 16.7%, p = 0.153) in patients with Boston Bowel Preparation Scale (BBPS) ≥6 over BBPS <6. Comparing patients with BBPS = 9 over BBPS = 7-8, no significant differences were found in PDR (34.5% vs. 38.4%, p = 0.483) nor ADR (24.1% vs. 27.2%, p = 0.553). At multivariable regression analysis, older age (OR = 1.042, 95%CI = 1.021-1.063; p < 0.001), shorter intubation time (OR = 0.891, 95%CI = 0.816-0.972; p = 0.010), higher withdrawal time (OR = 1.171, 95%CI = 1.094-1.253; p < 0.001) and full consumption of the first dose (OR = 8.368, 95%CI = 1.025-68.331; p = 0.047) were independently associated with ADR.

CONCLUSIONS

This post-hoc analysis of a RCT showed that excellent cleansing (BBPS = 9) over high-quality cleansing (BBPS = 7-8) does not significantly improve PDR or ADR. Neither cleansing success nor preparation types were independently associated with ADR. Compliance with bowel preparation, timing of colonoscopy and withdrawal time are key elements for adequate ADR with potential implications for reducing interval colorectal cancer.

A randomized, controlled trial of oral sulfate solution versus polyethylene glycol for bowel preparation for colonoscopy

BACKGROUND

The quality of colonoscopy is significantly influenced by the effectiveness of bowel preparation. In this study, we aimed to evaluate the efficacy, safety, and tolerability of bowel cleansing between a new oral sulfate solution (OSS) and standard polyethylene glycol electrolyte powder (PEG).

METHODS

This single center, randomized, superiority study recruited 679 outpatients who were assigned to either the new OSS group (Group A) or standard PEG group (Group B). The quality of bowel cleansing was evaluated using the Boston Bowel Preparation Scale (BBPS) and compared between the two groups. Furthermore, data pertaining to the duration of bowel preparation, patient tolerability, and the occurrence of adverse events were also analyzed.

RESULTS

According to BBPS scores, group A demonstrated significantly higher bowel preparation cleanliness than group B. Additionally, group A achieved superior bowel cleansing, as evidenced by a greater proportion of patients with BBPS scores ≥ 8 compared to group B (75.3% vs. 55.2%, P < 0.05). No severe adverse events were reported during examinations in either group.

CONCLUSIONS

The magnesium sulfate, sodium sulfate, and potassium sulfate concentrated oral solution is a novel, safe, and effective bowel preparation for colonoscopy.

TRIAL REGISTRATION

This study was registered in the Chinese Clinical Trial Registry on 20/02/2024 (clinical trial registration number: ChiCTR2400081004).

Comparative efficacy of different bowel preparations for colonoscopy: A network meta-analysis

BACKGROUND AND AIMS

The quality of a colonoscopy is heavily reliant on the effectiveness of bowel cleansing. Various cleansing solutions are currently available, but their comparative efficacy remains uncertain. This systematic review and network meta-analysis aims to compare the performance of different bowel preparations for colonoscopy.

METHODS

MEDLINE, Embase, Scopus, and the Cochrane Library were systematically searched for randomized controlled trials (RCTs) comparing the efficacy of different bowel preparations. The primary outcome was cleansing success (CS), and the secondary outcome was adenoma detection rate (ADR).

RESULTS

On network meta-analysis for CS (22 RCTs, 7179 patients, 14 bowel preparations), 2 L PEG + simethicone (RR = 1.25 [95 %CI = 1.13-1.37]), 2 L PEG + lactulose (RR = 1.22 [95 %CI = 1.10-1.38]) and 1 L PEG + ascorbate (ASC) (RR = 1.03 [95 %CI = 1.01-1.06]) were significantly superior to 2 L PEG + ASC. Overall, 2 L PEG + lactulose resulted as the best product (SUCRA 0.94), followed by 2 L PEG + simethicone (SUCRA 0.93). On network meta-analysis for ADR (17 RCTs, 6639 patients, 11 bowel preparations), only 2 L PEG + simethicone (RR = 1.60 [95 %CI = 1.05-2.43]) resulted significantly superior to 2 L PEG + ASC.

CONCLUSIONS

2 L PEG + simethicone, 2 L PEG + lactulose, and 1 L PEG + ASC seemed to provide high rates of CS, albeit only 2 L PEG + simethicone was associated with significantly higher ADR. Consequently, these products should be preferred for bowel preparation of colonoscopy. Further randomized studies with adequate sample sizes are needed for a more accurate comparison of these products on ADR.

Comparing 1-L and 2-L Polyethylene Glycol with Ascorbic Acid for Small Bowel Capsule Endoscopy: A Randomized Controlled Trial

Background/Aims

Small bowel capsule endoscopy (SBCE) has become the standard for initial evaluation in the diagnosis of small bowel lesions. Although optimal visualization of the mucosa is important, patients experience difficulty in consuming a large volume of bowel preparation agents. This study aimed to compare the efficacy and safety of 1-L polyethylene glycol (PEG) with ascorbic acid (AA) and 2-L PEG with AA.

Methods

In this prospective, multicenter, non-inferiority study, patients who received SBCE were randomly assigned to consume 1-L PEG with AA or 2-L PEG with AA for small bowel preparation. The primary outcome was adequate small bowel visibility quality (SBVQ). The secondary outcomes included diagnostic yield, cecal complete rate, and adverse events.

Results

One hundred and forty patients were enrolled in this study, 70 patients per group. In the per-protocol analysis, there were no significant differences in the adequate SBVQ rate (94.0% vs 94.3%; risk difference, -0.3; 95% confidence interval, -8.1 to 7.6; p=1.000), diagnostic yield rate (49.3% vs 48.6%, p=0.936), or cecal complete rate (88.1% vs 92.9%, p=0.338) between the 1-L PEG with AA group and 2-L PEG with AA group. The incidence of adverse events did not differ significantly between the groups (12.9% vs 11.9%, p=0.871).

Conclusions

One liter-PEG with AA is not inferior to 2-L PEG with AA in terms of adequate SBVQ for SBCE. One liter-PEG with AA can be recommended as the standard method for bowel cleansing for SBCE.

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.

Superior bowel preparation quality for colonoscopy with 1L-PEG compared to 2L-PEG and picosulphate: Data from a large real-world retrospective outpatient cohort

BACKGROUND

Several randomized clinical trials comparing different bowel preparations (BP) have shown similar efficacy; however, there is a lack of real-world studies on this topic.

AIMS

This study aims to identify the most effective BP regimen in a real-world setting and any predictors of inadequate BP.

METHODS

A retrospective single-center study was conducted over 14 months at an academic hospital including outpatient colonoscopies in which adult patients did not teach on how to perform BP before colonoscopy. Colonoscopies with 1L-PEG, 2L-PEG and picosulphate mixtures were considered. A multivariable analysis for factors associated to poor BP was fitted.

RESULTS

Overall, 1779 patients (51 %F, 60±14) years were included. The 1L-PEG regimen provided a higher rate of BP adequacy at multivariate analysis (adjusted OR 2.30, 95 %CI 1.67-3.16,p < 0.001) and was associated with higher median Boston Bowel Preparation Scale score (p < 0.001), higher rate of right-colon cleansing (p < 0.001) and exam completion (p = 0.04). Furthermore, we identified male sex, history of constipation, active smoking, previous pelvic surgery, concomitant psychiatric/neurological or chronic kidney diseases as predictors of inadequate BP.

CONCLUSIONS

This is the largest real-world study comparing 1L-PEG to other BP regimens. Our results suggest 1L-PEG provides better BP in a non-controlled setting, improving clinical practice quality and minimizing the need for repeated colonoscopies and saving healthcare resources.

SIED-GISCOR recommendations for colonoscopy in screening programs: Part I - Diagnostic

The implementation of FIT programs reduces incidence and mortality from CRC in the screened subjects. The ultimate efficacy for CRC morbidity and mortality prevention in a FIT program depends on the colonoscopy in FIT+ subjects that has the task of detecting and removing these advanced lesions. Recently, there has been growing evidence on factors that influence the quality of colonoscopy specifically withing organized FIT programs, prompting to dedicated interventions in order to maximize the benefit/harm ratio of post-FIT colonoscopy. This document focuses on the diagnostic phase of colonoscopy, providing indications on how to standardise colonoscopy in FIT+ subjects, regarding timing of examination, management of antithrombotic therapy, bowel preparation, competence and sedation.

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.

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.

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.

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.

Multi-center study of residual gastric volume and bowel preparation after the usage of 1L and 2L polyethylene glycol in Korea

BACKGROUND

In colonoscopy, good bowel preparation is an important factor in determining the quality of colonoscopy. However, an increase in residual gastric volume (RGV) can lead to a higher risk of aspiration pneumonia. Therefore, the purpose of this study was to investigate the factors related to an increase in RGV with the usage of 1L polyethylene glycol (PEG).

METHODS

We prospectively analyzed 268 patients who underwent both gastroscopy and colonoscopy at 2 hospitals from May to October 2021. Bowel preparation was performed using 1L in 127 patients (47.4%) and 2L PEG in 141 patients (52.6%). We investigated the time taken for bowel preparation solutions, the last water intake, total water intake, and RGV, and conducted a survey on taking compliance and satisfaction.

RESULTS

The level of RGV was significantly increased in the 1L PEG group when compared to the 2L PEG group (1L, 52.26 ± 65.33 vs 2L, 23.55 ± 22.99; P < .001). There was no difference between the 2 groups in the degree of bowel preparation, but there were more bubbles formed in the 1L group (1L, 1.91 ± 2.74 vs 2L, 1.10 ± 2.02; P = .007). In the case of RGV ≥ 50 mL, in multivariate analysis, the risk was higher in water intake within 5 hours and the patients who think the dose is too high (all P < .05).

CONCLUSION

Therefore, since RGV is higher in 1L PEG than in 2L PEG, it is necessary to be careful not to take water for at least 5 hours before the test.

Key factors for improving adenoma detection rate

INTRODUCTION

Colonoscopy is a fundamental tool in colorectal cancer (CRC) prevention. Nevertheless, one-fourth of colorectal neoplasms are still missed during colonoscopy, potentially being the main reason for post-colonoscopy colorectal cancer (PCCRC). Adenoma detection rate (ADR) is currently known as the best quality indicator correlating with PCCRC incidence.

AREAS COVERED

We performed a literature review in order to summarize evidences investigating key factors affecting ADR: endoscopists education and training, patient management, endoscopic techniques, improved navigation (exposition defect), and enhanced lesions recognition (vision defect) were considered.

EXPERT OPINION

'Traditional' factors, such as split dose bowel preparation, adequate withdrawal time, and right colon second view, held a significant impact on ADR. Several devices and technologies have been developed to promote high-quality colonoscopy, however artificial intelligence may be considered the most promising tool for ADR improvement, provided that endoscopists education and recording are guaranteed.