Randomized trial of 2-L polyethylene glycol + ascorbic acid versus 4-L polyethylene glycol as bowel cleansing for colonoscopy in an optimal setting

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

BACKGROUND AND AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Efficacy and tolerability of 1 L polyethylene glycol plus ascorbic acid with senna versus 2 L polyethylene glycol plus ascorbic acid for colonoscopic bowel preparation: Prospective, randomized, investigator-blinded trial

OBJECTIVES

Low-volume polyethylene glycol plus ascorbic acid (PEG-Asc) reduces the dosage of colonoscopic bowel preparation (BP) solution, but is still poorly tolerated. Adding laxatives to the BP solution reduces the volume of fluid required, without affecting quality. This study aimed to compare 1 L PEG-Asc plus 24 mg senna (1L-PEG/AS) and conventional 2 L PEG-Asc (2L-PEG/A) regimens on BP quality and patient tolerability.

METHODS

A single-center, randomized, investigator-blinded, noninferiority trial was performed between June and August 2022. Outpatients scheduled for colonoscopy were randomized (1:1) to the 1L-PEG/AS or 2L-PEG/A group. The Boston Bowel Preparation Scale (BBPS) was used to evaluate BP quality. Adverse events and tolerability were surveyed using questionnaires.

RESULTS

Overall, 344 patients received 1L-PEG/AS or 2L-PEG/A regimens. The baseline characteristics and adverse events of the two groups were comparable. The 1L-PEG/AS group showed noninferior adequate BP rates compared with the 2L-PEG/A group (88% vs. 89%, P = 1.00); overall BBPS was 7.1 ± 1.5 and 7.2 ± 1.5, respectively (P = 0.39). Higher willingness to repeat the BP was observed in the 1L-PEG/AS group (85% vs. 62%, P < 0.01).

CONCLUSIONS

The 1L-PEG/AS regimen was comparable to the 2L-PEG/A regimen in terms of BP adequacy, requiring lower BP solution volumes, with better patient tolerance. Thus, it may be a suitable alternative to the conventional BP solution for colonoscopy. The Japan Registry of Clinical Trials (jRCT1051220043).

Efficacy and safety of 1 L polyethylene glycol plus ascorbic acid for bowel preparation in elderly: comparison with oral sulfate solution

BACKGROUND/AIMS

Recently, 1 L of polyethylene glycol (PEG) plus ascorbic acid (Asc) has been introduced in Korea as a colonoscopy preparation agent. Data on its efficacy and safety in older adults have been limited. We aimed to evaluate the safety and efficacy of 1 L PEG/Asc in older adults by comparing it with oral sulfate solution (OSS).

METHODS

A prospective multicenter randomized study was conducted with subjects aged ≥ 65 years who underwent colonoscopy. The participants were randomized to receive 1 L PEG/Asc or OSS. The primary endpoint was successful bowel preparation, defined as total Boston Bowel Preparation Scale ≥ 6, and ≥ 2 at each segment. Patient satisfaction, adverse events, and renal function changes were compared between the groups.

RESULTS

Among the 106 patients, 104 were finally included in the analysis. Overall, successful bowel preparation was achieved in 96.2% of both 1 L PEG/Asc and OSS groups. The satisfaction scores for taste, total amount ingested, overall feeling, and willingness to repeat the same regimen were not significantly different between the groups. Adverse events of moderate or higher severity occurred in 16 and 10 cases in the 1 L PEG/Asc and OSS group, respectively. There were no significant changes in electrolyte levels or renal function from baseline.

CONCLUSION

The successful bowel preparation rate was > 90% in both groups without severe adverse effects and significant changes in renal function. As a new low-dose preparation regimen for colonoscopy in older adults, 1 L PEG/Asc, is as effective and safe as OSS.

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.

Observation of the application effect of low-volume polyethylene glycol electrolyte lavage solution (PEG-ELS) combined with ascorbic acid tablets in bowel preparation for colonoscopy in hospitalized patients

Background

This study explored the effectiveness and safety of low-volume polyethylene glycol electrolyte lavage solution (PEG-ELS) combined with ascorbic acid tablets (PEG-ELS/Asc) in bowel preparation for a colonoscopy.

Methods

A total of 240 hospitalized patients who underwent a colonoscopy in Wenzhou People's Hospital, Wenzhou Third Clinical College of Wenzhou Medical University from July 2020 to June 2022 were randomly divided into two groups, with 120 patients each. All of the participants were given a low-residue or residue-free diet one day before the examination and fasted after dinner (completed before 18:00) the day before the examination. The 2-L PEG-ELS/Asc group took 2-L PEG-ELS plus 10 g ascorbic acid tablets once orally, while the 3-L PEG-ELS group took 3-L PEG orally on several occasions. The primary endpoint was the achievement of preparation adequacy and an overall colon cleansing score of ≥6, both assessed by blinded investigators using the Boston Bowel Preparation Scale (BBPS). The bowel cleansing effect, polyp detection rate, adverse reaction rate, oral drug tolerance rate, renal function, and electrolyte level changes were also compared between the two patient groups.

Results

There were no significant differences in the success rate of bowel preparation, the detection rate of polyps, or the adverse reaction rate between the two groups (P > 0.05). The tolerance rate of bowel preparation in the 2-L PEG-ELS/Asc group was significantly higher than that in the 3-L PEG-ELS group (93.3% vs. 80.23%) (P < 0.05). The levels of creatinine, serum potassium, serum sodium, and serum chlorine of the two groups before and after bowel preparation were within the normal range. In addition, the intestinal cleaning effect of the two preparation schemes for the hospitalized patients with diabetes and constipation is worse than that of those without these conditions (P < 0.05).

Conclusion

The effectiveness and safety of using 2-L PEG-ELS/Asc in bowel preparation for a colonoscopy in hospitalized patients were not inferior to using 3-L PEG-ELS. For patients with diabetes and constipation, the cleansing effect of the two bowel preparation options was not very satisfactory, and further clinical research is needed in this regard.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

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.

Combination of bisacodyl suppository and 1 L polyethylene glycol plus ascorbic acid is a non-inferior and comfortable regimen compared to 2 L polyethylene glycol plus ascorbic acid

BACKGROUND AND AIM

Appropriate bowel cleansing before colonoscopy is an important factor in increasing the detection rate of lesions. Low-volume polyethylene glycol (PEG) plus ascorbic acid (PEG-Asc) reduces the dosage of bowel preparation agent, but still presents discomfort to patients. The primary aim of the present study was to compare the efficacy of bowel cleansing between 2 L PEG-Asc (control) and 1 L PEG-Asc with bisacodyl suppository (suppository) groups, and the secondary aim was to investigate complications and tolerability between the two groups.

METHODS

This was a single-center prospective randomized controlled study. We identified 168 patients scheduled for colonoscopy between August 2017 and January 2018 and randomly assigned them to the control or to the suppository groups. Efficacy of bowel cleansing was assessed using the Boston Bowel Preparation Scale (BBPS), and side-effects were surveyed using questionnaires.

RESULTS

No significant difference was detected in baseline characteristics including insertion and withdrawal times, and adenoma detection rates between the two groups. Total BBPS score was 7.93 ± 1.06 and 7.74 ± 1.02 in the control and suppository groups, respectively (P = 0.22). Incidence of abdominal pain and nausea was not statistically different, whereas that of sleep disturbance and anal discomfort was higher in the control group. (P = 0.00).

CONCLUSIONS

One liter PEG-Asc with bisacodyl suppository resulted in an equivalent bowel-cleansing outcome with reduced patient discomfort compared to 2 L PEG-Asc. Therefore, PEG-Asc with bisacodyl suppository represents a potential alternative and increases patient compliance with bowel preparation.

Comparison of Oral Sulfate Solution and Polyethylene Glycol Plus Ascorbic Acid on the Efficacy of Bowel Preparation

Background/Aims

The quality of bowel preparation is one of the quality indicators for colonoscopy. The aim of this study was to compare the efficacy of oral sulfate solution (OSS) and polyethylene glycol plus ascorbic acid (PEG-AA) for bowel preparation.

Methods

The study involved 167 patients who underwent diagnostic colonoscopies. Inadequate bowel preparation was defined as any score of ≤1 in each colon section based on the Boston Bowel Preparation Scale. Multivariate logistic regression was used to compare the efficacy of OSS and PEG-AA. Subgroup analyses were performed based on patient characteristics.

Results

Overall, 106 (63.5%) patients received OSS, and 61 (36.5%) patients received PEG-AA. The rate of inadequate bowel preparation was 12.3% in patients receiving OSS and 32.8% in patients receiving PEG-AA (p=0.001). OSS (odds ratio [OR] = 0.26; p=0.003) and morning examination (OR=0.11; p=0.038) were significantly associated with efficient bowel preparation. The efficacy of OSS compared with PEG-AA was only significant in patients ≥50 years of age vs. <50 years of age (OR=0.13; p=0.001 vs. OR=0.96; p=0.959) and female vs. male patients (OR=0.06; p=0.002 vs. OR=0.58; p=0.339).

Conclusions

OSS was significantly more efficient for bowel preparation than PEG-AA, especially in patients ≥50 years of age and female patients. Morning examination led to a good quality of bowel preparation, irrespective of the preparation regimen.

[Optimal Laxatives for Oral Colonoscopy Bowel Preparation: from High-volume to Novel Low-volume Solutions]

Optimal bowel preparation is essential for a more accurate, comfortable, and safe colonoscopy. The majority of postcolonoscopy colorectal cancers can be explained by procedural factors, mainly missed polyps or inadequate examination. Therefore the most important goal of optimal bowel preparation is to reduce the incidence of colorectal cancer. Although adequate preparation should be achieved in 85-90% or more of all colonoscopy as a quality indicator, unfortunately 20-30% shows inadequate preparation. Laxatives for oral colonoscopy bowel preparation can be classified into polyethylene glycol (PEG)-electrolyte lavage solution, osmotic laxatives, stimulant laxatives, and divided into high-volume solution (≥3 L) and low-volume solution (<3 L). The updated 2019 European Society of Gastrointestinal Endoscopy (ESGE) guideline is broadly similar to the 2014 American Society for Gastrointestinal Endoscopy (ASGE) recommendations and reaffirms the importance of split-dosing. However, new ESGE guideline, unlike the 2014 ASGE recommendation, suggests the use of high volume or low volume PEG-based regimens as well as that of non-PEG based agents that have been clinically validated for most outpatient scenarios. For effective, safe, and highly adherent bowel preparation, physicians who prescribe and implement colonoscopy should properly know the advantages and limitations, the dosing, and the timing of regimens. Recently many studies have attempted to find the most ideal regimens, and more convenient, effective, and safe regimens have been developed by reducing the dosing volume and improving the taste. The high tolerability and acceptability of the new low-volume regimens suggest us how we should use it to increase the participation of the national colorectal cancer screening program.

Novel sulfate tablet PBK-1701TC versus oral sulfate solution for colon cleansing: A randomized phase 3 trial

BACKGROUND AND AIM

PBK-1701TC is a novel sulfate tablet-based that contains 320 mg of simethicone and delivers 90% of the salt and water delivered by oral sulfate solution (OSS) preparation. This study evaluated the efficacy, safety, and tolerability of PBK-1701TC compared with OSS in bowel preparation for colonoscopy.

METHODS

This randomized, multicenter, phase 3 non-inferiority trial included adults aged 19 years or older with a body mass index of 19-30 kg/m2 undergoing colonoscopy at five university hospitals in Korea. The primary efficacy endpoint was successful bowel-cleansing rate, defined as Harefield Cleansing Scale grade A or B as evaluated by blinded central readers. Secondary endpoints included the presence of residual air bubbles. Adverse events and laboratory evaluations were monitored to assess safety. Tolerability was assessed via participant interview.

RESULTS

Overall, 235 participants were randomized, and 224 were included in the per-protocol analysis (PBK, 112; OSS, 112). Successful bowel cleansing was achieved for 95.5% (107/112) in the PBK group, which was non-inferior to the OSS group (98.2%, 110/112) with a difference of -2.7% (one sided 97.5% confidence limit, -8.1%). The participants in the PBK group had fewer intraluminal bubbles (0.9% vs 81.3%, P < 0.001) and reported a lower incidence of nausea and vomiting, with better acceptance, taste, and willingness to repeat the regimen than those in the OSS group (all P < 0.05).

CONCLUSION

The novel sulfate tablet, PBK-1701TC, was non-inferior to OSS with respect to bowel-cleansing efficacy and exhibited better safety and tolerability in adults undergoing colonoscopy.

Improved high-quality colon cleansing with 1L NER1006 versus 2L polyethylene glycol + ascorbate or oral sulfate solution

BACKGROUND & AIMS

Colonoscopy requires bowel cleansing for gut mucosa visualization; high-quality cleansing facilitates lesion detection. NER1006 is a 1L polyethylene glycol (PEG) bowel preparation. This post hoc analysis of two randomized trials investigated cleansing efficacy assessed, as in clinical practice, by site endoscopists.

METHODS

Patients received NER1006, 2L PEG + ascorbate (2LPEG), or oral sulfate solution (OSS) as a 2-day evening/morning regimen (N2D) or NER1006 morning-only dosing (N1D). Treatment-blinded site endoscopists assessed cleansing using the Harefield Cleansing Scale (HCS). Analyses were conducted in a modified full analysis set, including (mFAS; n = 1378) or excluding (mFAS2; n = 1319) imputed failures, and in patients with 100% treatment adherence (mFAS100; n = 1047). Overall cleansing success (HCS grade A/B), overall high-quality cleansing (HCS grade A), and high-quality segments (HCS 3-4) per treatment population were analyzed.

RESULTS

Overall cleansing success was higher with N2D than 2LPEG (92.7-97.5% vs. 87.9-93.0%), and more patients had overall high-quality cleansing with N2D and N1D than 2LPEG (68.0-72.1% and 64.0-68.4% vs. 50.7-56.0%). Without imputed failures, N2D delivered more overall high-quality cleansing than OSS (74.5-77.3% vs. 67.8-69.8%). More high-quality segments were demonstrated with N2D and N1D versus 2 LPEG (82.5-87.1% and 79.4-84.4% vs. 70.4-76.3%) and with N2D versus OSS (82.7-89.5% vs. 78.1-84.4%).

CONCLUSION

When assessed by site endoscopists, NER1006 delivers greater high-quality cleansing than 2LPEG or OSS.

A Randomized Controlled Trial Comparing Colonoscopic Enema With Additional Oral Preparation as a Salvage for Inadequate Bowel Cleansing Before Colonoscopy

GOALS

The goal of this study was to evaluate the noninferiority of colonoscopic enema to additional oral preparation in salvage bowel cleansing for inadequate preparation for a morning colonoscopy.

BACKGROUND

Colonoscopic enema, administering additional cathartics into the right colon through the colonoscope accessory channel, is suggested to rescue poor bowel preparation for a colonoscopy but lacking comparative study.

STUDY

In this prospective, randomized, actively-controlled, parallel group, noninferiority trial, consecutive outpatients and health checkup recipients aged from 19 to 70 years with inappropriate bowel preparation during an elective colonoscopy were enrolled to receive either a colonoscopic enema of 1 L polyethylene glycol (PEG) (enema group) or additional oral intake of 2 L PEG (oral group). The primary endpoint was the proportion of adequate bowel preparation evaluated using the Boston Bowel Preparation Scale.

RESULTS

Overall, 131 participants were randomized. Adequate bowel preparation was achieved in 53% (35/66) of the enema group, which was significantly inferior to the oral group (81.5%; 53/67) with a difference of -28.5% (95% confidence interval, -44.1, -12.9; P=0.001). The largest difference in the proportion of adequate bowel preparation was observed in the right colon (57.8% in the enema group vs. 86.9% in the oral group; P<0.001), followed by the transverse colon (85.9% vs. 98.4%; P=0.017) and the left colon (90.6% vs. 96.7%; P=0.274).

CONCLUSIONS

The colonoscopic enema of 1 L PEG was inferior to the additional oral ingestion of 2 L PEG regarding efficacy as a salvage bowel preparation in adults with inadequate bowel cleansing for colonoscopy.

Comparative Efficacy of 2 L Polyethylene Glycol Alone or With Ascorbic Acid vs. 4 L Polyethylene Glycol for Colonoscopy: A Systematic Review and Network Meta-Analysis of 12 Randomized Controlled Trials

Background: Colonoscopy remains an optimal approach for early detection and treatment of gastrointestinal lesions, however adequate bowel preparation is the critical contributor to effective and safe colonoscopy. Polyethylene glycol (PEG)-based bowel cleansing regime has been the first recommendation before colonoscopy, however it remains unknown which regime is the optimal option. Aim: The aim of our study is to determine the comparative efficacy of 2 L PEG alone or plus ascorbic acid (Asc) vs. 4 L PEG alone for bowel cleansing prior to colonoscopy. Methods: We assigned two independent investigators to search and screen potential records, extract essential information, and appraise the risk of bias of individual study accordingly. Then, we adopted RevMan 5.3, Stata 14.0, and WinBUGS 1.4 software to perform all statistical analyses. We also calculated the surface under the cumulative ranking curve (SCURA) in order to rank all regimes. Results: Twelve studies involving 4,106 patients were analyzed finally. Pooled results indicated an improved bowel preparation efficacy in 2 L PEG plus ascorbic acid with split-dose regime rather than in 2 L PEG plus ascorbic acid (OR, 0.25; 95% CI, 0.18-0.36), 4 L PEG with split dose (OR, 3.18; 95% CI, 2.17-4.66), and 4 L PEG (OR, 4.53; 95% CI, 3.07-6.67) regimes, which was confirmed by network meta-analyses; a better compliance in 2 L PEG plus Asc with split dose (OR, 3.08; 95% CI, 1.51-6.30) and 4 L PEG with split dose (OR, 0.43; 95% CI, 0.22-0.82) regime rather than in 4 L PEG regime, but network meta-analyses generated inconsistency results; a higher preference in 2 L PEG plus Asc with split dose regime rather than in 4 L PEG split dose (OR, 2.24; 95% CI, 1.02-4.90), which were not supported by network meta-analyses; no statistically significant difference when all regimes compared with each other in terms of adverse events. Conclusions: As for bowel preparation before colonoscopy, 2 L PEG ascorbic acid with split dose should be optimally prescribed. Further studies investigating the comparative efficacy of 2 L PEG related to 4 L PEG, 4 L PEG with split dose, and 2 L PEG plus ascorbic acid with split dose, respectively are needed.

The Efficacy of Split-Dose Bowel Preparations for Polyp Detection: A Systematic Review and Meta-Analysis

INTRODUCTION

Split-dose bowel preparation leads to superior colon cleansing for colonoscopy. However, the magnitude of benefit in detecting colonic polyps is uncertain. We performed a systematic review to synthesize the data on whether using a split-dose bowel preparation regimen improves the detection of polyps when compared with other dosing methods or regimen products.

METHODS

We searched MEDLINE, EMBASE, and CENTRAL databases (from the inception to June 2017) for randomized controlled trials that assessed the following: split-dose vs day-before, split-dose vs same-day (as colonoscopy), or different types of split-dose regimens for patients undergoing colonoscopy. We excluded studies limited to inpatients, children, or individuals with inflammatory bowel disease. We compared the number of patients undergoing colonoscopy with recorded detection of polyps, adenomas, advanced adenomas, sessile serrated polyps (SSPs), right colonic adenomas, right colonic polyps, or right colonic SSPs.

RESULTS

Twenty-eight trials fulfilled the inclusion criteria (8,842 participants). Of the seven trials comparing split-dose vs day-before bowel preparation regimens, there was an increased detection rate of adenomas (risk ratio (RR) 1.26, 95% confidence intervals (CIs): 1.10-1.44; 4 trials; 1,258 participants), advanced adenomas (RR 1.53, 95% CI: 1.22-1.92; 3 trials; 1,155 participants), and SSPs (RR 2.48, 95% CI: 1.21-5.09; 2 trials; 1,045 participants). Pooled estimates from 8 trials (1,587 participants) evaluating split-dose vs same-day bowel preparations yielded no evidence of statistical difference. For various split-dose vs split-dose trials, 14 fulfilled the criteria (5,496 participants) and no superior split-regimen was identified.

CONCLUSIONS

Compared with day-before bowel preparation regimens, split-dose bowel preparations regimens increase the detection of adenomas, advanced adenomas, and have the greatest benefit in SSP detection.

Novel 1 L polyethylene glycol-based bowel preparation (NER1006): proof of concept assessment versus standard 2 L polyethylene glycol with ascorbate - a randomized, parallel group, phase 2, colonoscopist-blinded trial

Background

Colonoscopy requires colon cleansing. For this, many polyethylene glycol (PEG)-based preparations still require a high preparation-volume intake. Using an increased osmotic load with ascorbate (Asc), five new low-volume PEG-based bowel preparations (LVPEG) were tested for clinical proof of concept.

Methods

This two-part, open-label study examined preparation-volumes of 1–1.25 L and total required fluid volumes of 2–3 L. Part 1, in healthy volunteers, used mean cumulative 24-h stool weight (target > 2750 g) to identify a lead candidate. Part 2 was endoscopist-blinded: patients undergoing screening colonoscopy were randomized before treatment with the selected lead, one of two variants of it, or the control 2 L PEG + Asc. Two primary endpoints were used for proof of concept demonstration: mean 24-h stool weight and bowel cleansing success (Harefield Cleansing Scale).

Results

A total of 120 subjects (30 per group) were enrolled/randomized 1:1:1:1 (max 40:60 gender ratio) per completed Part. In Part 1, LVPEG-3 achieved the largest mean stool weight (3399 g: P < 0.0001 vs target) and was selected for Part 2. In Part 2, stool weights exceeded the target, notably for LVPEG-4 (3215 g: P < 0.001), which achieved 100% cleansing success after a total required fluid intake of 2 L. The control achieved 90% cleansing success. Adverse events were few, gastrointestinal in nature and similar between groups.

Conclusions

LVPEG-4 achieved a clinically useful combination of cleansing, safety/tolerability and low consumption volume: 1 L preparation + 1 L required additional fluid. Named NER1006, LVPEG-4 demonstrated clinical proof of concept and warrants further investigation.

Trial registration

October 2012.

Identifier: NCT01714466. EudraCT: 2012–003052-37

The trial was prospectively registered.

Electronic supplementary material

The online version of this article (10.1186/s12876-019-0988-y) contains supplementary material, which is available to authorized users.

Low-Volume Polyethylene Glycol Improved Patient Attendance in Bowel Preparation Before Colonoscopy: A Meta-Analysis With Trial Sequential Analysis

Background: Polyethylene glycol (PEG) has been regarded as the primary recommendation for bowel preparation before colonoscopy. However, a conclusive conclusion has not yet been generated.

Aim: We performed this updated meta-analysis to further investigate the comparative efficacy and safety of low volume preparation based on PEG plus ascorbic acid related to 4L PEG.

Methods: A systematic search was conducted to retrieve potential randomized controlled trials (RCTs) in PubMed, EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL) from January 2000 to April 2018. Two independent searchers critically searched all potential citations, extracted data, and appraised risk of bias accordingly. Moreover, we used the STATA 12.0 and trial sequential analysis (TSA) 0.9 to complete all analyses.

Results: A total of 13 RCTs enrolling 3,910 patients met inclusion criteria. Meta-analysis based on PP analysis indicated that compared to standard volume PEG regime, low volume regime improved patient compliance RR = 1.01; 95% CIs = 1.00, 1.03; P = 0.143 (≥75% intake); RR = 1.07; 95% CIs = 1.00, 1.14; P = 0.046 (100% intake), the willingness to repeat the same regime (RR = 1.30; 95% CIs = 1.07, 157; P = 0.007), and patient acceptability (RR = 1.18; 95% CIs = 1.07, 1.29; P = 0.001), and decreased the overall adverse events (RR = 0.86; 95% CIs = 0.77, 0.96; P = 0.009). However, no difference was observed between these two different solutions for bowel preparation efficacy (RR = 0.98; 95% CIs = 0.95, 1.02; P = 0.340). These all results were further confirmed by TSA.

Conclusions: The effect of low volume regime was not inferior to the standard volume PEG regime, and low volume regime was associated with better compliance when subjects ingested all the solution, willingness to repeat the same regime, higher acceptability, and lower nausea in non-selected population.

Comparative efficacy of low volume versus traditional standard volume PEG on bowel preparation before colonoscopy: Protocol for an updated meta-analysis with trial sequential analysis

INTRODUCTION

Polyethylene glycol (PEG) has been considered as the first recommendation for bowel preparation prior to colonoscopy. A previous meta-analysis suggested that low volume PEG may improve the acceptability of ingesting bowel preparation solution. However, several limitations impaired the power of findings from this published meta-analysis, such as the variation in study design of included trials and adjuvant prescriptions. Moreover, some studies related to this topic have been published recently. And thus, the aim of this updated meta-analysis is to further assess the comparative efficacy of low volume versus standard volume of PEG on bowel preparation before colonoscopy with trial sequential analysis (TSA).

METHODS AND ANALYSIS

Systematic searches will be performed to capture any potential randomized controlled trials (RCTs) investigated the comparative efficacy of low volume versus traditional standard volume PEG on bowel preparation prior to colonoscopy in PubMed, EMBASE, and Cochrane Central Register of Controlled Trials. Moreover, we will also manually check the bibliographies of related studies and reviews so as to get additional studies. Two reviewers will independently screen the citation records, extract essential information, and appraise the risk of bias of each RCT in sequence. Finally, we will used the STATA software version 12.0 and TSA software version beta 0.9 to statistically analyze all data and test the robust of each pooled result, respectively.

RESULTS

We will submit the full-text of systematic review to a peer-review journal for publication.

CONCLUSION

This updated systematic review and meta-analysis with TSA will further assess the comparative efficacy and safety of low-volume versus traditional standard volume PEG for bowel preparation prior to colonoscopy. And then, a more comprehensive evidence body on low-volume compared to standard volume PEG in bowel preparation will be constructed.

Optimal intake of clear liquids during preparation for afternoon colonoscopy with low-volume polyethylene glycol plus ascorbic acid

BACKGROUND AND STUDY AIMS

The standard colonoscopy preparation regimen in Japan for afternoon procedures is sequential intake of 1 L of polyethylene glycol electrolyte lavage solution containing ascorbic acid (PEG-ASC), 0.5 L of clear liquid, 0.5 L of PEG-ASC, and finally 0.25 L of clear fluids (all at a rate of 0.25 L every 15 min). However, this regimen seems poorly tolerated and complicated for many patients compared to previous regimen of polyethylene glycol electrolyte lavage solution. The aim of this study was to evaluate an alternate regimen of 0.5 L of PEG-ASC followed by 0.25 L clear liquids, repeated 3 times.

PATIENTS AND METHODS

This was a single-blinded, non-inferiority, randomized controlled study. Subjects were randomized to the standard regimen or the alternate regimen using a web-based registry system. All patients were instructed to eat a pre-packaged, low residue diet and to take sodium picosulfate hydrate the day before colonoscopy. The Boston Bowel Preparation Scale was used to evaluate bowel cleansing, and a 3-point scale was used to assess mucosal visibility. The primary endpoint was successful bowel cleansing. The acceptability, tolerability, safety, and endoscopic findings of these two regimens were secondary endpoints.

RESULTS

 A total of 409 patients were randomized to either the standard regimen (n = 204, males 54.0 %, mean age 65.5 years) or the alternate regimen (n = 205, 54.6 %, 65.0 years). The rates of successful bowel cleansing were 71.1 % (64.3 - 77.2 %) with the standard regimen vs. 75.1 % (68.6 - 80.9 %) with the alternate regimen (95 % lower confidence limit, for the difference = - 4.6, non-inferiority P  < 0.05). No significant differences were found in tolerability, safety, and endoscopic findings.

CONCLUSION

 The alternate regimen and standard regimen are clinically equivalent with respect to cleansing efficacy and acceptability, tolerability, safety, and endoscopic findings. These results are good news for patients with difficulty drinking the first liter of PEG-ASC.

Comparative Evaluation of the Efficacy of Polyethylene Glycol With Ascorbic Acid and an Oral Sulfate Solution in a Split Method for Bowel Preparation: A Randomized, Multicenter Phase III Clinical Trial

BACKGROUND

An adequate level of bowel preparation before colonoscopy is important. The ideal agent for bowel preparation should be effective and tolerable.

OBJECTIVE

The purpose of this study was to compare the clinical efficacy and tolerability of polyethylene glycol with ascorbic acid and oral sulfate solution in a split method for bowel preparation.

DESIGN

This was a prospective, multicenter, randomized controlled clinical trial.

SETTINGS

Outpatients at the specialized clinics were included.

PATIENTS

A total of 186 subjects were randomly assigned. After exclusions, 84 subjects in the polyethylene glycol with ascorbic acid group and 83 subjects in the oral sulfate solution group completed the study and were analyzed.

INTERVENTIONS

Polyethylene glycol with ascorbic acid or oral sulfate solution in a split method was the included intervention.

MAIN OUTCOME MEASURES

The primary end point was the rate of successful bowel preparation, which was defined as being excellent or good on the Aronchick scale. Tolerability and adverse events were also measured.

RESULTS

Success of bowel preparation was not different between 2 groups (91.7% vs 96.4%; p = 0.20), and the rate of adverse GI events (abdominal distension, pain, nausea, vomiting, or abdominal discomfort) was not significantly different between the 2 groups. In contrast, the mean intensity of vomiting was higher in the oral sulfate solution group than in the polyethylene glycol with ascorbic acid group (1.6 ± 0.9 vs 1.9 ± 1.1; p = 0.02).

LIMITATIONS

All of the colonoscopies were performed in the morning, and the subjects were offered enhanced instructions for bowel preparation. In addition, the results of tolerability and adverse effect may have a type II error, because the number of cases was calculated for confirming the efficacy of bowel preparation.

CONCLUSIONS

Oral sulfate solution is effective at colonoscopy cleansing and has acceptable tolerability when it is compared with polyethylene glycol with ascorbic acid. The taste and flavor of oral sulfate solution still need to be improved to enhance tolerability.

Is a split-dose regimen of 2 L polyethylene glycol plus ascorbic acid tolerable for colonoscopy in an early morning visit to a comprehensive medical check-up?

AIM

To evaluate the effectiveness and tolerability of a split-dose 2 L polyethylene glycol (PEG)/ascorbic acid (AA) regimen for healthy examinees who visited for comprehensive medical check-up in the early morning.

METHODS

From February 2015 to March 2015, examinees of average risk who were scheduled for a colonoscopy in the morning were retrospectively enrolled.

RESULTS

The 189 examinees were divided into split-dose and non-split-dose groups. The adequacy of bowel preparation for the split-dose group vs the non-split-dose group was 96.8% vs 85.2%, respectively, P < 0.001, and the compliance of the last meal restriction was 74.6% vs 58.2%, respectively, P < 0.001. The sleep disturbance (P < 0.001) was more prevalent in the split-dose group, however the willingness to repeat the same preparation method (P = 0.243) was not different in both groups. The split-dose regimen was the most important factor influencing adequate bowel preparation in multivariate analysis (HR = 10.89, 95%CI: 6.53-18.17, P < 0.001).

CONCLUSION

A split-dose regimen of 2 L PEG/AA for an early morning colonoscopy was more effective and showed better compliance for diet restriction without any difference in satisfaction and discomfort. Introducing a split-dose regimen of 2 L PEG/AA to morning colonoscopy examinees is effective and tolerable in a comprehensive medical check-up setting.

Randomized trial comparing oral sulfate solution with 4-L polyethylene glycol administered in a split dose as preparation for colonoscopy

BACKGROUND AND AIM

The present study aimed to evaluate the non-inferiority of low-volume oral sulfate solution (OSS) to 4-L polyethylene glycol (PEG) solutions administered in a split-dose regimen as bowel preparation for colonoscopy. The safety and tolerability were also compared between the two regimens.

METHODS

In this prospective, randomized, single-blind, active-control, parallel group, and non-inferiority trial, consecutive outpatients and health checkup recipients aged 19-65 years undergoing elective colonoscopy were enrolled to receive OSS or 4-L PEG in a split-dose regimen. The quality of bowel preparation was evaluated using the Boston Bowel Preparation Scale. The occurrence of any adverse events, acceptance, compliance, and satisfaction during bowel preparation were evaluated by participant interviews.

RESULTS

Overall, 210 participants were randomized, and 199 were administered by the study agents. Adequate bowel preparation was achieved in 98.0% (97/99) of the OSS group, which was non-inferior to the PEG group (96%; 96/100) with a difference of +2.8% (95% confidence interval; -2.8, +6.8). There were no differences in the incidence of adverse events except for abdominal pain, which was more frequent in the OSS (7.1%, 7/99) than in the PEG (1.0%, 1/100; P = 0.035) group. Acceptance, compliance, and satisfaction were significantly higher in the OSS than in the PEG group (all P < 0.05).

CONCLUSIONS

Split-dose OSS was non-inferior to split-dose 4-L PEG with regard to bowel preparation efficacy before colonoscopy in adult outpatients or screening colonoscopy recipients aged ≤65 years with acceptable safety and superior tolerability.

Polyethylene glycol plus ascorbic acid for bowel preparation in chronic kidney disease

The safety of polyethylene glycol plus ascorbic acid has not been fully investigated in patients with renal insufficiency. High-dose ascorbic acid could induce hyperoxaluria, thereby causing tubule-interstitial nephritis and renal failure. This study aims to evaluate the safety and efficacy of polyethylene glycol plus ascorbic acid in patients with chronic kidney disease.We retrospectively reviewed prospectively collected data on colonoscopy in patients with impaired renal function. Patients were divided into 2 groups: 2 L polyethylene glycol plus ascorbic acid (n = 61) and 4 L polyethylene glycol (n = 80). The safety of the 2 groups was compared by assessing the differences in laboratory findings before and after bowel cleansing.The laboratory findings were not significantly different before and after the administration of 2 L polyethylene glycol plus ascorbic acid or 4 L polyethylene glycol. In both groups, the estimated glomerular filtration rate was not influenced by the administration of the bowel-cleansing agent. Patients' reports on tolerance and acceptability were better in the 2 L polyethylene glycol plus ascorbic acid group than in the 4 L polyethylene glycol group.The 2 L polyethylene glycol plus ascorbic acid solution is a safe choice for bowel preparation before colonoscopy in patients with impaired renal function.

Does Polyethylene Glycol (PEG) Plus Ascorbic Acid Induce More Mucosal Injuries than Split-Dose 4-L PEG during Bowel Preparation?

BACKGROUND/AIMS

The aims of this study were to compare the bowel-cleansing efficacy, patient affinity for the preparation solution, and mucosal injury between a split dose of polyethylene glycol (SD-PEG) and low-volume PEG plus ascorbic acid (LV-PEG+Asc) in outpatient scheduled colonoscopies.

METHODS

Of the 319 patients, 160 were enrolled for SDPEG, and 159 for LV-PEG+Asc. The bowel-cleansing efficacy was rated according to the Ottawa bowel preparation scale. Patient affinity for the preparation solution was assessed using a questionnaire. All mucosal injuries observed during colonoscopy were biopsied and histopathologically reviewed.

RESULTS

There was no significant difference in bowel cleansing between the groups. The LV-PEG+Asc group reported better patient acceptance and preference. There were no significant differences in the incidence or characteristics of the mucosal injuries between the two groups.

CONCLUSIONS

Compared with SD-PEG, LV-PEG+Asc exhibited equivalent bowel-cleansing efficacy and resulted in improved patient acceptance and preference. There was no significant difference in mucosal injury between SD-PEG and LV-PEG+Asc. Thus, the LV-PEG+Asc preparation could be used more effectively and easily for routine colonoscopies without risking significant mucosal injury.

A Randomized Controlled Trial Evaluating a Low-Volume PEG Solution Plus Ascorbic Acid versus Standard PEG Solution in Bowel Preparation for Colonoscopy

Evaluation of polyethylene glycol electrolyte lavage solution containing ascorbic acid (PEG-ASC) has been controversial in the point of its hyperosmolarity, especially in old population. So we therefore designed the present study to compare the efficacy, acceptability, tolerability, and safety of 1.5 L PEG+ASC and 2 L standard PEG electrolyte solution (PEG-ELS), not only in the general population, but also in patients of advanced age. Randomization was stratified by age (<70 years or 70> years), and hematological and biochemical parameters were compared in each age group, especially with respect to the safety profile of each regimen. As a result, the 1.5-L PEG-ASC regimen had higher patient acceptability than the 2-L PEG-ELS regimen. Tolerability, bowel cleansing, and safety were similar between regimens. However, we demonstrated significant statistical changes in the hematological and biochemical parameters after taking bowel preparation solutions, not only in the PEG+ASC group, but also in the PEG-ELS group. No significant differences in the safety profile were found between subjects aged less than 70 years and those aged 70 years or more; nevertheless, regardless of age, proper hydration is needed throughout the bowel preparation process.

The use of low-volume polyethylene glycol containing ascorbic acid versus 2 L of polyethylene glycol plus bisacodyl as bowel preparation for colonoscopy

OBJECTIVE

Low-volume polyethylene glycol (PEG) bowel preparations have been developed to improve compliance for colonoscopy. Our study aimed to compare the efficacy and tolerability of low-volume PEG containing ascorbic acid for colonoscopy against 2 L of PEG plus bisacodyl.

METHODS

We prospectively enrolled consecutive inpatients who had not undergone polypectomy at the index colonoscopy and were subsequently referred for polypectomy at our hospital. A total of 62 patients were randomized to receive either low-volume PEG containing ascorbic acid (n = 31) or 2 L of PEG plus bisacodyl (n = 31) as a split-dose regimen in inpatients. The efficacy of preparation was determined using the Ottawa Bowel Preparation Score (OBPS) and a 4-point scale. Adverse events, tolerability, and willingness were evaluated using a questionnaire.

RESULTS

Based on the OBPS and 4-point scale, we determined that the efficacy of low-volume PEG containing ascorbic acid was comparable to that of the 2 L of PEG plus bisacodyl (p = 0.071 for OBPS, p = 0.056 for the 4-point scale). Adverse events were comparable between the two groups (p = 1.000). A greater proportion of patients in the low-volume PEG containing ascorbic acid (90.6%) and the 2L of PEG plus bisacodyl (96.9%) were willing to repeat the same preparation for subsequent colonoscopy.

CONCLUSION

Low-volume PEG containing ascorbic acid had comparable efficacy and tolerability to 2 L of PEG plus bisacodyl, when given as a split dose, for colonoscopy in inpatients. Split-dose low-volume PEG containing ascorbic acid is a good alternative for bowel preparation for colonoscopy in inpatients.

Patient descriptions of rectal effluents may help to predict the quality of bowel preparation with photographic examples

Background/Aims

Previous studies have suggested a weak correlation between self-reported rectal effluent status and bowel preparation quality. We aim to evaluate whether photographic examples of rectal effluents could improve the correlation between patient descriptions of rectal effluents and bowel preparation quality.

Methods

Before colonoscopy, patients were asked to describe the nature of their last three rectal effluents. Photographic examples of rectal effluents were provided as a reference for scoring. Bowel preparation was subsequently assessed by a single endoscopist using a global preparation assessment scale. Preparation outcomes were grouped into two levels (excellent to good vs. fair to inadequate). Both univariate and multivariate logistic regression models were used to find any association between bowel preparation quality and patient characteristics.

Results

A total of 138 patients completed the questionnaires. The mean age was 56.5±10.4 years. The mean sum of the last three rectal effluent scores was 5.9±2.0. Higher rectal effluent scores (odds ratio [OR], 0.82; P=0.043) and the presence of diverticula (OR, 0.16; P<0.001) were risk factors for suboptimal preparation.

Conclusions

Photographic example-guided patient descriptions of rectal effluents showed a statistically significant association with bowel preparation quality. However, clinical significance seemed to be low. The presence of diverticula was an independent predictive factor for suboptimal bowel preparation quality.

3-L split-dose is superior to 2-L polyethylene glycol in bowel cleansing in Chinese population: a multicenter randomized, controlled trial

Large volume (4 L) of polyethylene glycol (PEG) solution would ensure a better quality of bowel cleansing but might be poorly tolerated. Due to the smaller body size, lower body weight, and different diet habits, the large volume of 4-L PEG might be poorly tolerated by the Chinese population. In view of this, a balance should be made between the volume and effectiveness. This study aimed to compare the effectiveness, compliance, and safety between 3-L split-dose and 2-L PEG in Chinese population. Consecutive patients scheduled for colonoscopy were recruited from 5 tertiary medical centers in South China between April and July, 2014. Patients were prospectively randomized into 2 groups: 3-L split-dose PEG (3L-group) and 2 L PEG (2L-group). The primary endpoint was bowel cleansing and was defined according to Ottawa Bowel Preparation Scale (OBPS). The safety and compliance were also evaluated. A total of 318 patients were included in the analysis. The mean total OBPS score was significantly higher in 2L-group than in 3L-group (4.4 ± 2.7 vs 2.9 ± 2.4, P < 0.001). Both the intention-to-treat and per-protocol analysis found that rates of successful and excellent bowel preparation were much higher in 3L-group (89.9% and 78.0%) than 2L-group (79.2% and 48.4%), respectively (P < 0.001). The average cecum intubation time was significantly shorter in 3L-group (8.2 ± 3.7 min) than in 2L-group (10.3 ± 4.2 min) (P = 0.04). Adenoma detection rate in right colon was slightly higher in 3L-group than in 2L-group (17.6% vs 12.6%, P = 0.21). The safety and compliance including the taste, smell, and dosage of PEG were similar between 2 groups (P > 0.05). 3-L split-dose PEG is superior to 2-L PEG by better bowel cleansing, improved safety and compliance, shorter cecum intubation time, and potentially higher adenoma detection rate in rightward colon in Chinese population.