Validation of the Harefield Cleansing Scale: a tool for the evaluation of bowel cleansing quality in both research and clinical practice

Performance of bowel preparation quality scales in patients with Crohn's disease

BACKGROUND

The performance of bowel preparation (BP) in patients with Crohn's disease (CD) is unknown.

AIMS

To evaluate the operating properties of instruments used to assess BP quality in patients with CD.

METHODS

We used the Boston Bowel Preparation Scale, modified Boston Bowel Preparation Scale, Harefield Cleansing Scale, Food and Drug Administration Bowel Cleansing Assessment Scale (BCAS), and a 100-mm visual analogue scale of bowel cleanliness to assess BP quality in 50 videos from 40 patients with CD. We assessed endoscopic activity with the Simple Endoscopic Score for CD (SES-CD). Assessments were on endoscope insertion and withdrawal. Reliability was quantified using the intraclass correlation coefficient (ICC). We assessed validity by within-patient correlation between instruments and the visual analogue scale using mixed-effect models. The correlation between BP quality and SES-SD scores was assessed using Spearman's rho.

RESULTS

Inter- and intra-rater reliability for all BP quality instruments was substantial (ICC ≥0.61) except for the Food and Drug Administration BCAS on insertion (inter-rater reliability ICC ≥0.41). The visual analogue scale had substantial inter- and almost perfect (ICC ≥0.81) intra-rater reliability. Correlation coefficients for the validity of the instruments exceeded 0.58. BP quality and endoscopic disease activity scores in the colon were negatively correlated.

CONCLUSION

Most existing instruments reliably assess BP quality in patients with CD. These results support the use of these instruments in clinical practice, provide a framework for scoring BP quality in CD clinical trials, and support evaluation of novel BP agents in patients with CD.

Efficacy, tolerability, and safety of oral sulfate tablet versus 2 L-polyethylene glycol/ascorbate for bowel preparation in older patients: prospective, multicenter, investigator single-blinded, randomized study

BACKGROUND

We compared the efficacy, tolerability, and safety of oral sulfate tablets (OST, which contains simethicone) and 2 L-polyethylene glycol/ascorbate (2 L-PEG/Asc) with a split-dosing regimen in older individuals aged ≥ 70 years who underwent scheduled colonoscopy.

METHODS

This prospective, randomized, investigator-blinded, multicenter study was conducted between June 2022 and October 2023. Participants aged ≥ 70 years were randomized at a ratio of 1:1 to the OST or 2 L-PEG/Asc groups.

RESULTS

In total, 254 patients were evaluated using a modified full analysis set. Successful overall bowel preparation was excellent and similar between the OST and 2 L-PEG/Asc groups for the Boston Bowel Preparation Scale (BBPS) (96.5% vs. 96.6%) and Harefield Cleansing Scale (HCS) (96.5% vs. 97.4%). The overall high-quality preparation rate was higher in the OST group than in the 2 L-PEG/Asc group (BBPS: 55.7% vs. 28.4%, P < 0.001; HCS: 66.1% vs. 38.8%, P < 0.001). The overall adenoma detection rate (54.8% vs. 35.3, P = 0.003) was superior in the OST group compared to the 2 L-PEG/Asc group. Tolerability scores, including overall satisfaction, were generally higher in the OST group than in the 2 L-PEG/Asc group. The incidence of major solicited adverse events was comparable between the two groups (55.7% vs. 68.1, P = 0.051), and there were no clinically significant changes in the serum laboratory profiles on the day of or 7 days after colonoscopy.

CONCLUSIONS

OST is an effective and safe low-volume agent for colonoscopy, with better tolerance than 2 L-PEG/Asc, in older individuals aged ≥ 70 years.

Comparison of a novel mini-oral sulfate tablet and the conventional oral sulfate tablet in bowel preparation for colonoscopy: a prospective, randomized, investigator-blinded, multicenter, non-inferior, phase 3 trial

BACKGROUND AND AIMS

The use of conventional oral sulfate tablets (OSTs) has gained popularity; nonetheless, they may be not only inconvenient to swallow but also difficult to dissolve. A novel mini-OST has recently been developed to enhance compliance with conventional OST use. This study aimed to compare the efficacy, tolerability, and safety between mini-OST and conventional OST.

METHODS

This was a prospective, randomized, investigator-blinded, multicenter, and non-inferior phase 3 trial conducted between September 2022 and December 2022. The efficacy, safety, and tolerability were compared between mini-OST and conventional OST.

RESULTS

Exactly 83 patients were evaluated based on a full analysis set (FAS), whereas 82 patients were evaluated as a per-protocol set (PPS). With respect to the efficacy of preparation, successful and high-quality preparation was excellent in the mini-OST and conventional OST groups on both FAS and PPS analyses, without significant differences between the two groups. On the FAS analysis, the satisfaction and tolerability scores were high in both groups, without significant differences. The first bowel movement after taking the investigational product occurred 30 min earlier in the mini-OST group than in the OST group. Mild, moderate, and severe adverse events (AEs) were comparable between the two groups; however, any AEs were more common in the mini-OST group than in the conventional OST group overall.

CONCLUSIONS

Compared with conventional OST, the novel mini-OST preparation showed similar efficacy, tolerability, and safety, including mild eight solicited AEs and moderate-to-severe AEs. Clinical trial registration NCT05670470.

Interobserver Variation of Bowel Preparation for Colonoscopy

BACKGROUD/AIMS

Several bowel preparation scales have been developed, but they are variably validated to guide clinical practice. The aim of this study was to assess the interobserver reliability between internal and external endoscopists using the Harefield Cleaning Scale (HCS).

METHODS

Data was collected from a study evaluating the efficacy of oral sulfate tablets in patients undergoing colonoscopy. The assessments of bowel cleansing were carried out by four internal endoscopists at the time of the procedure, and colonoscopy video recordings were reviewed independently by three external endoscopists. Interobserver reliability was quantified using Cohen's Kappa coefficient, and scores and grades of each segment were compared between internal and external endoscopist groups.

RESULTS

Among 83 colonoscopy videos, interobserver reliability yielded a fair agreement between internal and external endoscopists, with a Cohen's Kappa coefficient of 0.39 (95% CI 0.08-0.70). Successful overall preparation rates (100% vs 98.8%) and high-quality preparation rates (88% vs 94%) were excellent and comparable between the two groups. In contrast, one case of unsuccessful cleansing (grade C) was documented, only in the external group. In addition, the interobserver reliability between internal and external endoscopists comparing each segmental score yielded a slight agreement in the descending colon (0.11, 95% CI - 0.02 to 0.23) and sigmoid colon (0.04, 95% CI - 0.18 to 0.26).

DISCUSSION

Interobserver reliability between internal and external endoscopists using the HCS was fair. However, the HCS may be limited as a reliable scale for assessing bowel preparation quality in the left colon, where liquid is mainly retained in the left lateral position.

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

BACKGROUND AND OBJECTIVES

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

CONCLUSIONS

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

SPLIT-DOSE BOWEL PREPARATION IS SUPERIOR TO STRAIGHT-DOSE IN HOSPITALIZED PATIENTS UNDERGOING INPATIENT COLONOSCOPY

BACKGROUND

There is a two-fold higher rate of failed colonoscopy secondary to inadequate bowel preparation among hospitalized versus ambulatory patients. Split-dose bowel preparation is widely used in the outpatient setting but has not been generally adapted for use among the inpatient population.

OBJECTIVE

The aim of this study is to evaluate the effectiveness of split versus single dose polyethylene glycol bowel (PEG) preparation for inpatient colonoscopies and determine additional procedural and patient characteristics that drive inpatient colonoscopy quality.

METHODS

A retrospective cohort study was performed on 189 patients who underwent inpatient colonoscopy and received 4 liters PEG as either split- or straight-dose during a 6-month period in 2017 at an academic medical center. Bowel preparation quality was assessed using Boston Bowel Preparation Score (BBPS), Aronchick Score, and reported adequacy of preparation.

RESULTS

Bowel preparation was reported as adequate in 89% of the split-dose group versus 66% in the straight-dose group (P=0.0003). Inadequate bowel preparations were documented in 34.2% of the single-dose group and 10.7% of the split-dose group (P<0.001). Only 40% of patients received split-dose PEG. Mean BBPS was significantly lower in the straight-dose group (Total: 6.32 vs 7.73, P<0.001).

CONCLUSION

Split-dose bowel preparation is superior to straight-dose preparation across reportable quality metrics for non-screening colonoscopies and was readily performed in the inpatient setting. Interventions should be targeted at shifting the culture of gastroenterologist prescribing practices towards use of split-dose bowel preparation for inpatient colonoscopy.

Comparison of optimal bowel cleansing effects of 1L polyethylene glycol with ascorbic acid versus sodium picosulfate with magnesium citrate: A randomized controlled study

Various low-volume bowel cleansing formulations that improve compliance have been approved and are being used in clinical practice. This study aimed to compare the effectiveness of 1 L polyethylene glycol (PEG) with ascorbic acid with that of sodium picosulfate (PICO) with magnesium citrate. This was a multicenter, randomized controlled, non-inferiority study. Patients were randomized into a 1 L PEG with ascorbic acid group and a PICO with magnesium citrate group according to the bowel cleansing agent used. Colonoscopy was performed as a single-blind study wherein the endoscopist had no information about any bowel preparation agent. The efficacy of bowel cleansing was assessed using the Harefield Cleansing Scale (HCS), and adverse events, preferences, and satisfaction were evaluated using a patient-reported questionnaire before colonoscopy. A total of 254 participants were randomly assigned to two groups: 115 in the 1 L PEG with ascorbic acid group and 113 in the PICO with magnesium citrate group. Overall bowel cleansing success was not statistically different between the two groups (97.4 vs. 97.3%), confirming that 1 L PEG with ascorbic acid was not inferior to PICO with magnesium citrate (lower confidence limit, -4.15%; p = 1.00). High-quality bowel cleansing was achieved in 87% of the 1 L PEG with ascorbic acid group and 77% of the PICO with magnesium citrate group (Lower confidence limit, 1.29%, p = 0.05). In terms of patient satisfaction, PICO with magnesium citrate was better, but compliance and side effects were similar in both groups. The 1 L PEG with ascorbic acid showed similar efficacy and adverse events as PICO with magnesium citrate. Although 1 L PEG with ascorbic acid is very effective in bowel preparation despite its small volume, it is necessary to increase satisfaction such as taste and feeling.

An Expert Consensus to Standardize Assessment of Bowel Cleansing for Clinical Trials of Bowel Preparations for Crohn's Disease

BACKGROUND

Despite regular need for colonoscopy in patients with Crohn's disease (CD), the efficacy and tolerability of bowel preparation (BP) agents is rarely assessed in this population. Assessing BP quality with existing scales may be challenging in CD due to presence of inflammation, bowel resection, and strictures.

AIMS

To provide recommendations for assessing BP quality in clinical trials for CD using a modified Research and Development/University of California, Los Angeles appropriateness process.

METHODS

Based on systematic reviews and a literature search, 110 statements relating to BP quality assessment in CD were developed. A panel of 15 gastroenterologists rated the statements as appropriate, uncertain, or inappropriate using a 9-point Likert scale.

RESULTS

Panelists considered it appropriate that central readers, either alone or with local assessment, score BP quality in clinical trials. Central readers should be trained on scoring BP quality and local endoscopists on performing high-quality video recording. Both endoscope insertion and withdrawal phases should be reviewed to score BP quality in each colonic segment and segments should align with endoscopic disease activity indices. The Harefield Cleansing Scale and the Boston Bowel Preparation Scale were considered appropriate. The final score should be calculated as the average of all visualized segments. Both total and worst segment scores should also be assessed.

CONCLUSIONS

We developed a framework for assessing BP quality in patients with CD based on expert feedback. This framework could support the development or refinement of BP quality scales and the integration of BP quality assessment in future CD studies.

Efficacy, safety and tolerability of oral sulphate tablet for bowel preparation in patients with inflammatory bowel disease: A multicentre randomized controlled study

BACKGROUND AND AIMS

We evaluated the efficacy, safety and tolerability of novel oral sulphate tablets [OSTs] vs 2 L of polyethylene glycol and ascorbate [PEG/Asc] in patients with inflammatory bowel disease [IBD].

PATIENTS AND METHODS

A total of 110 patients with clinically inactive IBD were enrolled in this single-blind multicentre non-inferiority study. Patients were randomly assigned to the OST or 2 L PEG/Asc group and we applied a split-dose regimen. The primary efficacy endpoint was bowel cleansing success rate defined as Harefield Cleansing Scale Grade A or B. The secondary endpoints were perfect preparation rate, the presence of air bubbles, safety as assessed by laboratory abnormalities and self-reported adverse events, or IBD symptom flare-ups. Tolerability was assessed by a pre-procedural visual analog scale [VAS] interview.

RESULTS

Both groups showed high cleansing success rates [98.1%] and there was no significant difference in perfect preparation rate. The proportion of a bubble score 0 was significantly higher in the OST group [94.5% vs 50.0%, p < 0.001]. There was no significant intergroup difference in vomiting or bloating. Symptom flare-ups occurred in two OST group patients. No clinically significant blood test abnormalities were noted in either group. Ease of ingestion and taste scores were significantly higher in the OST group. More patients in the OST group [94.5%] wanted to take the same preparation agent for their next colonoscopy.

CONCLUSIONS

Both OST and 2 L PEG/Asc demonstrated high successful cleansing and safety in patients with inactive IBD. OST achieved higher satisfaction than 2 L PEG/Asc. Our results suggest that the OST split-dose regimen is effective and safe for patients with inactive IBD.

Existing Bowel Preparation Quality Scales Are Reliable in the Setting of Centralized Endoscopy Reading

BACKGROUND

Development of bowel preparation products has been based upon colon cleansing rating by a local endoscopist. It is unclear how bowel preparation scales perform when centrally evaluated.

AIMS

To evaluate the reliability of bowel preparation quality scales when assessed by central readers.

METHODS

Four central readers evaluated 52 videos in triplicate, 2 weeks apart, during the entire endoscopic procedure (insertion/withdrawal of the colonoscope) and exclusively on colonoscope withdrawal using the Boston Bowel Preparation Scale (BBPS), Chicago Bowel Preparation scale, Harefield Cleansing Scale, Ottawa Bowel Preparation Quality Scale (OBPQS), Aronchick score, a visual analogue scale, and additional items proposed in a modified Research and Development/University of California Los Angeles appropriateness process. Reliability was assessed with intraclass correlation coefficients.

RESULTS

Intraclass correlation coefficients (95% confidence interval) for inter-rater reliability of the quality scales ranged from 0.51 to 0.65 (consistent with moderate to substantial inter-rater reliability) during the entire procedure. Corresponding intraclass correlation coefficients for intra-rater reliability ranged from 0.69 to 0.77 (consistent with substantial intra-rater reliability). Reliability was highest in the right colon and lowest in the left colon. No differences were observed in reliability when assessed for the procedure overall (insertion/withdrawal) relative to assessment on withdrawal alone.

CONCLUSION

All five bowel preparation quality scales had moderate to substantial inter-rater reliability. Panelists considered the Aronchick score too simplistic for clinical trials and recognized that assessment of residual fluid in the Ottawa Bowel Preparation Quality Scale was not amenable to central assessment.

Improving the tolerability and safety of 1-L polyethylene glycol plus low-dose ascorbic acid for bowel preparation in a healthy population: a randomized multicenter clinical trial

BACKGROUND AND AIMS

One-liter polyethylene glycol plus ascorbic acid (PEG-ASC) improves patient tolerability, but some patients still show low tolerability to a relatively high content of ASC. This study aimed to improve the tolerability and safety of 1-L PEG with low-dose ASC in comparison with standard 1-L and 2-L PEG-ASC.

METHODS

This was a randomized, controlled, double-blinded, multicenter, noninferiority trial involving 215 healthy adults who underwent colonoscopy from June 2020 to January 2021. Efficacy, tolerability, and safety were compared among 1-L PEG with low-dose ASC (50% lower ASC concentration in group A and 25% lower ASC concentration in groups B and C) and standard 1-L and 2-L PEG-ASC with all split regimens.

RESULTS

One-liter PEG with low-dose ASC (groups A-C) had similar bowel cleansing efficacies according to the Harefield Cleansing Scale and Boston Bowel Preparation Scale, without negative clinical performance, compared with standard 1-L and 2-L PEG-ASC preparation (all P > .1). One-liter PEG with low-dose ASC had better tolerability compared with 2-L PEG-ASC and less residual fluid retention in the stomach compared with 1-L PEG-ASC, proportional to the amount of ASC. No significant differences were found in the incidences of overall adverse events, mild adverse events, or death or in the occurrence of gastroduodenal erosion or ulcer in upper endoscopy.

CONCLUSIONS

One-liter PEG with low-dose ASC (25%-50% reduction in dose) for bowel cleansing showed similar efficacy and safety compared with standard 1-L or 2-L PEG-ASC, better tolerability compared with 2-L PEG-ASC, and less residual gastric fluid retention compared with standard 1-L PEG-ASC. (Clinical trial registration number: KCT0005490.).

Use of Insoluble Dietary Fiber and Probiotics for Bowel Preparation Before Colonoscopy: A Prospective Study

BACKGROUND

In screening colonoscopy, patients usually have to ingest large amounts of bowel-cleansing agents, including polyethylene glycol (PEG). This is difficult and has various side effects; thus, patients avoid undergoing a colonoscopy. We tested a novel bowel preparation method before colonoscopy using insoluble dietary fiber and probiotics (PB).

METHODS

This was a prospective clinical study conducted between October 2018 and March 2019 at a general hospital. Forty participants were randomly assigned to low-volume PEG solution diet (MoviPrep), wheat bran fiber (WBF) and probiotic Bifidobacterium animalis subsp. lactis GCL2505 (PB GCL2505), or standard-volume regimen (1.0 to 1.5 L of MoviPrep) (control group). The patient compliance and the quality of bowel preparation were evaluated.

RESULTS

Forty individuals aged 38 to 83 years were randomly assigned to the WBF with PB (n=20) and control (n=20) groups. All participants underwent bowel preparation before colonoscopy according to each protocol. The mean required volume of MoviPrep was significantly lower in the WBF with PB group than in the control group (582.5 vs. 1305 mL, P<0.0001). Successful bowel-cleansing rates were not significantly different between the 2 groups; however, the ratio of the Harefield Cleansing Scale grades C and D was significantly lower in the WBF with PB group than in the control group (P=0.0471).

CONCLUSIONS

The intake of WBF and GCL2505 before colonoscopy reduces the required PEG quantities while maintaining bowel-cleansing quality. This novel, minimally invasive pretreatment method makes colonoscopy more accessible contributing to the prevention and early treatment of colorectal cancer.

1 L- versus 2 L-polyethylene glycol with ascorbic acid for bowel preparation in elderly patients: a randomized multicenter study

BACKGROUND

1 L-polyethylene glycol (PEG)/ascorbic acid (Asc) was developed to reduce the required oral preparation volume through increasing osmotic load through containing a greater quantity of ascorbate components. We aimed to compare the efficacy, tolerability, and safety of a split-dosing regimen of 1 L-PEG/Asc versus 2 L-PEG/Asc in elderly patients undergoing scheduled colonoscopy.

METHODS

This was a prospective, non-inferiority, randomized, investigator-blinded multicenter study conducted in Korea between July 2019 and December 2020. Patients aged between 65 and 85 years were randomized at a ratio of 1:1 to either the 1 L-PEG/Asc or 2 L-PEG/Asc group. The efficacy of the bowel preparation was evaluated using the Harefield Cleansing Scale (HCS) and the Boston Bowel Preparation Scale (BBPS).

RESULTS

A total of 202 patients were analyzed. Successful overall bowel preparation was similar between the 1 L-PEG/Asc and 2 L-PEG/Asc groups based on HCS (95.1% vs. 93.1%, P = 0.528) and BBPS (93.1% vs. 90.0%, P = 0.422). The perfect overall bowel preparation rate in the 1 L-PEG/Asc group was higher than that in the 2 L-PEG/Asc group (HCS, 40.2% vs. 25.0%, P = 0.021; BBPS, 80.4% vs. 68.0%, P = 0.044). There were more high-quality bowel preparations for the right colon in the 1 L-PEG/Asc group (HCS, 46.1% vs. 30.0%, P = 0.019; BBPS, 83.3% vs. 70.0%, P = 0.025). The adenoma detection rate (47.1% vs. 49.0%, P = 0.782), rate of adverse events (25.5% vs. 23.0%, P = 0.680), shifts in laboratory results, and tolerability were comparable between the groups.

CONCLUSION

1 L-PEG/Asc was as effective, safe, and tolerable as 2 L-PEG/Asc in elderly patients with comorbidities.

Efficacy and Safety of TJP-008 Compared to 2 L PEG with Ascorbate in Colon Cleansing: A Randomized Phase 3 Trial

Background/Aims

Polyethylene glycol (PEG)-based bowel preparations are effective cleansing agents for colonoscopy. However, they require relatively large volumes to be used even with agents such as 2 L PEG with ascorbate (2LPEG). This phase 3, randomized, single-blinded, multicenter, parallel-group study compared the efficacy of 1 L PEG with high-dose ascorbate, TJP-008, to 2LPEG.

Methods

Patients undergoing colonoscopy were randomized (111) to receive TJP-008 as 1-day split dose (TJP-008-1) or 2-day split dose (TJP-008-2) regimen or to receive 2LPEG as a 2-day split dose regimen. Cleansing efficacy was evaluated using the Harefield Cleansing Scale. The primary endpoint was overall bowel cleansing success. Full analysis set (FAS) and per protocol set (PPS) analyses were performed.

Results

Of the 314 screened patients, efficacy was assessed in the following patient numbers (FAS/PPS) total (293/285), TJP-008-1 (98/94), TJP-008-2 (97/95), and 2LPEG (98/96). FAS revealed noninferiority between TJP-008 and 2LPEG with regard to overall success (TJP-008-2, 99.0%; TJP-008-1, 95.9%; 2LPEG, 94.9%; p=0.100 and p=0.733, respectively). PPS also showed noninferiority (p=0.721 and p=0.211, respectively). However, the PPS analyses showed a higher bowel cleansing score for TJP-008-2 for high-quality cleansing in the right colon (TJP-008-2 83.2% vs 2LPEG 62.5%; p=0.005).

Conclusions

TJP-008 is a new low-volume cleansing agent with a colon cleansing efficacy comparable to that of standard 2LPEG that exhibits significant safety and tolerability.

Bowel cleansing efficacy for colonoscopy: prospective, randomized comparative study of same-day dosing with 1-L and 2-L PEG + ascorbate

Background and study aims  Polyethylene glycol (PEG) bowel preparations are effective but associated with high ingestion volume. In this study, 1-L PEG and 2-L PEG preparations were compared in a randomized, colonoscopist-blinded, single-center trial. Patients and methods  Patients were aged > 18 years, required colonoscopy, and provided informed consent. Randomization was 1:1 to 1-L PEG or 2-L PEG, based on hospital identification number (odd or even). Preparations were administered using same-day dosing adjusted for colonoscopy start time. The primary endpoint was successful bowel preparation on the Boston Bowel Preparation Scale (BBPS) (no segment scored < 2). Results  A total of 852 patients were randomized. In the intention-to-treat (ITT) population, significantly more patients had diabetes in the 2-L PEG arm, resulting in the creation of the modified-ITT population (mITT) that excluded diabetic patients to correct the imbalance (1-L PEG, n = 239; 2-L PEG, n = 238). In the mITT, there was no significant difference in successful cleansing between 1-L PEG and 2-L PEG (88.3 % vs. 82.4 %; P  = 0.067). Excellent cleansing (BBPS 7-9; no segment < 2) was significantly improved with 1-L PEG (60.7 % vs. 50.4 %; P  < 0.024), as were mean scores in the right and left colon (right: 2.47 vs. 2.30; P  < 0.008; left: 2.55 vs. 2.39; P  = 0.008). Adverse events were mild to moderate in intensity and none resulted in discontinuation. Rates of nausea and vomiting were significantly higher with 1-L PEG, but that did not affect successful cleansing. Conclusions  The lower-volume 1-L PEG was associated with higher levels of excellent bowel cleansing and greater mean segmental scores on the BBPS than 2-L PEG.

The Efficacy of Simethicone With Polyethylene Glycol for Bowel Preparation: A Systematic Review and Meta-Analysis

BACKGROUND

Simethicone (SIM) is a commonly used antifoaming agent in the clinic. However, it has not been clarified whether SIM can improve the quality of intestinal preparation and the detection rates of adenomas (ADR) and polyps (PDR). This systematic review and meta-analysis were carried out to mainly evaluate the effect of SIM in bowel preparation for colonoscopy.

MATERIALS AND METHODS

An electronic and a manual search of the literature for studies was conducted in PubMed, EMBASE, and Web of Science in all published data before February 1, 2020. The primary outcomes were the quality of bowel preparation and the ADR and PDR. All the data were calculated using a pooled estimate of risk ratio with 95% confidence intervals, and a random-effect model was used for the calculation.

RESULTS

Eighteen randomized controlled trials with 7187 patients were included in this meta-analysis. Polyethylene glycol (PEG) with SIM improved colon cleansing (P<0.00001), PDR (P=0.006) and the detection rate of lesions in the right colon (P<0.00001) when compared with PEG alone. There was no difference in the ADR (P=0.68), withdrawal time (P=0.06), cecal intubation rate (P=0.98), and cecal intubation time (P=0.65) between 2 groups. The rate of abdominal bloating rate was higher in the PEG group, but there was no significant difference in vomiting (P=0.65), and abdominal pain (P=0.25).

CONCLUSIONS

SIM improves the quality of bowel cleanliness and PDR but not ADR. Besides, SIM improves the detection rate of lesions in the right colon and decreased abdominal bloating, but do not affect vomiting and abdominal pain or cramping.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

PLAIN LANGUAGE SUMMARY

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

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.

Improved detection of colorectal adenomas by high-quality colon cleansing

Background and study aims  Reliable adenoma detection requires "adequate" bowel preparation. The adenoma detection rate (ADR) was assessed in patients with high-quality (stool-free) cleansing versus adequate cleansing. Patients and methods  This study was a post-hoc combined analysis of three randomized trials individually powered for cleansing quality assessment. Treatment-independent ADR was assessed versus colon cleansing quality by central readers using the Harefield Cleansing Scale (HCS) and the Boston Bowel Preparation Scale (BBPS). The number needed to treat (NNT) to find an additional patient with at least one adenoma was calculated for high-quality versus adequate-quality cleansing. Results  A total of 1749 patients were included. ADR increased with high-quality versus adequate-quality cleansing: HCS grade A versus B, 39 % (94/242) versus 27 % (336/1229); NNT = 8.7; P  < 0.001. ADR also increased with high-quality versus uniform adequate segmental cleansing scores: HCS grade A versus uniform segmental scores 2, 39 % (94/242) versus 26 % (97/379); NNT = 7.5; P  < 0.001. ADR increased with top-quality versus adequate segmental cleansing scores: HCS uniform segmental scores 4 versus 2, 54 % (21/39) versus 26 % (97/379); NNT = 3.6; P  < 0.001. ADR increased with BBPS 9 versus 6, 43 % (71/166) versus 26 % (247/950); NNT = 6.0; P  < 0.001. Right colon ADR increased with top-quality versus adequate cleansing: HCS 4 versus 2, 20 % (25/122) versus 11 % (121/1117); NNT = 10.4; P  < 0.001 and BBPS 3 versus 2, 15 % (42/284) versus 11 % (130/1192); NNT = 25.8; P  = 0.033. Conclusions  High-quality colon cleansing improves adenoma detection, and it should be a priority for bowel preparations for colonoscopy.

High-quality colon cleansing and multiple neoplasia detection with 1L NER1006 versus mid-volume options: Post hoc analysis of phase 3 clinical trials

Background and study aims  Multiple neoplasia increase the risk of colorectal cancer. High-quality cleansing may improve adenoma detection. We assessed whether a new bowel preparation can improve colon cleansing and multiple lesion detection. Patients and methods  This post hoc analysis of two randomized clinical trials in Europe and the US assessed the per study and combined cleansing efficacy of overnight split dosing with (preparation + clear fluids) 1 + 1 L polyethylene glycol (PEG) NER1006 versus 2 + 1 L PEG + ascorbate (2LPEG) or 1 + 2 L oral sulfate solution (OSS) combined. Treatment-blinded central readers assessed cleansing quality using the Harefield Cleansing Scale (HCS). Patients with full segmental scoring were included. HCS segmental scores 0-4 (high-quality = HCS 3-4) were analyzed for NER1006 versus 2LPEG/OSS. Mean number of polyps or adenomas per patient (MPP/MAP) was calculated for treatments in patients with at least one polyp or adenoma. Results  In 1037 patients, NER1006 attained a greater rate of HCS 3 scores (29 % vs. 20 %; P  < 0.001) and HCS 4 scores (20 % vs. 17 %; P  = 0.007) versus 2LPEG/OSS. More polyps (678 versus 585) and adenomas (397 versus 331) were detected with NER1006 (N = 517) versus 2LPEG/OSS (N = 520). In all neoplasia-positive patients, with increasing minimal per-patient neoplasia multiplicity from 1 to 10, NER1006 numerically improved MPP (difference ± SE: 0.48 ± 0.24 to 3.89 ± 3.37) and MAP (0.47 ± 0.26 to 7.50 ± 9.00) versus 2LPEG/OSS. Conclusions  Low-volume NER1006 enhances high-quality cleansing versus medium-volume 2LPEG or OSS, individually and when combined. NER1006 may consequently facilitate the detection of multiple neoplasia in patients.

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

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

Reinforced education improves the quality of bowel preparation for colonoscopy: An updated meta-analysis of randomized controlled trials

Background and aims

Inadequate bowel preparation (BP) is an unfavorable factor that influence the success of colonoscopy. Although standard education (SE) given to patients are proved useful to avoid inadequate BP. Studies concerning the effects of reinforced education (RE) on the quality of BP were inconsistent. The aim of this updated meta-analysis of randomized controlled trial was to compare the quality of BP between patients receiving RE in addition to SE and those receiving SE alone.

Methods

MEDLINE, EMBASE, Web of Science and the Cochrane Library were systemically searched to identify the relevant studies published through April 2019. The primary outcome was the rate of adequate BP. Subgroup analyses were conducted. Secondary outcomes included BP score, adenoma detection rate (ADR), polyp detection rate (PDR), insertion time, withdrawal time, adverse events, >80% purgative intake and diet compliance. Dichotomous variables were reported as odds ratio (OR) with 95% confidence interval (CI). Continuous data were reported as mean difference (MD) with 95%CI. Pooled estimates of OR or MD were calculated using a random-effects model. Statistical heterogeneity was accessed by calculating the I2 value. A P value less than 0.05 was considered significant.

Results

A total of 18 randomized controlled trails (N = 6536) were included in this meta-analysis. Patients who received RE had a better BP quality than those only receiving SE (OR 2.59, 95%CI: 2.09–3.19; P<0.001). A higher ADR (OR 1.35; 95%CI: 1.06–1.72; P = 0.020) and PDR (OR 1.24, 95%CI: 1.02–1.50; P = 0.030), shorter insertion (MD -0.76; 95%CI: -1.48-(-0.04); P = 0.040) and withdrawal time (MD -0.83; 95%CI: -1.83-(-0.28); P = 0.003), less nausea/vomiting (OR 0.78; 95%CI: 0.64–0.97; P = 0.020) and abdominal distension (OR 0.72; 95%CI: 0.68–0.92; P = 0.020) were achieved in the RE group. More patients had >80% purgative intake (OR 2.17; 95%CI, 1.09–4.32; P = 0.030) and were compliant with diet restriction (OR 2.38; 95%CI: 1.79–3.17; P<0.001) in the RE group.

Conclusion

RE significantly improved BP quality, increased ADR and PDR, decreased insertion and withdrawal time and adverse events.

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.

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.

A Randomized Crossover Trial of Conventional vs Virtual Chromoendoscopy for Colitis Surveillance: Dysplasia Detection, Feasibility, and Patient Acceptability (CONVINCE)

BACKGROUND

Chromoendoscopy (CE) is the recommended surveillance technique for colitis, but uptake has been limited and the literature provides scant information on patient experience (PE); imperative to adherence to surveillance programmes. Virtual CE (VCE) by Fujinon Intelligent Colour Enhancement digitally reconstructs mucosal images in real time, without the technical challenges of CE. We performed a multifaceted randomized crossover trial (RCT) to evaluate study feasibility and obtain preliminary comparative procedural and PE data.

METHODS

Patients were randomized to undergo either CE with indigo carmine or VCE as the first procedure. After 3-8 weeks, participants underwent colonoscopy with the second technique. Patient recruitment/retention, missed dysplasia, prediction of dysplasia, and contamination (memory/sampling of the first procedure) were recorded. PE was assessed by validated questionnaires, and pain was assessed using a visual analog scale (mm).

RESULTS

Sixty patients were recruited, and 48 patients (first procedure: 23 VCE, 25 CE) completed the trial (retention 80%) with no episodes of contamination. Eleven dysplastic lesions were detected in n = 7/48 (14.5%). VCE missed 1 lesion, and CE missed 2 lesions in n = 2 (data of VCE vs CE, respectively, for dysplasia diagnostic accuracy: 93.94% [85.2%-98.32%] vs 76.9% [66.9%-98.2%]; examination time [minutes]: 14 +/- 4 vs 20 +/- 7 (95% confidence interval, 3.5 to 8; P < 0.001); pain (mm): 27.4 +/- 17.5 vs 34.7 +/- 18; patient preference: 67% [n = 31] vs 33% [n = 15] in n = 46; P < 0.001).

CONCLUSIONS

This is the first RCT to include validated PE in a colitis surveillance program. VCE is safe, technically easier, quicker, and more comfortable test, with dysplasia detection at least as good as that of CE, overcoming many barriers to the wider adoption of CE. This trial may serve as a successful foundation for a a multicenter trial to confirm the value of VCE for colitis surveillance.

A systematic review and cost analysis of repeat colonoscopies due to inadequate bowel cleansing in five European countries

Background: Colonoscopies are carried out for a range of reasons including for the detection of colon cancer and investigation of abdominal and bowel related symptoms. Inadequate preparation can increase the burden of repeat procedures.Methods: A systematic review aimed to identify the rate of repeat colonoscopies due to inadequate bowel preparation in France, Germany, Italy, Spain and the United Kingdom. The information obtained populated a decision analytic model to estimate the cost implications of inadequate bowel cleansing in the same five countries. The model explored scenarios by comparing one and two-litre polyethylene glycol-based bowel preparation.Results: The systematic review identified 14 eligible studies reporting on the proportion of patients with inadequate bowel cleansing indicated for a repeat procedure. Data were available for Italy (27.5%-35.9%), Spain (63%) and the UK (24.5%) only. The decision analytic model demonstrates that improving the proportion of adequate bowel cleansing at first colonoscopy is likely to generate cost savings.Conclusions: Based on the available evidence, increasing the proportion of people who have adequate bowel cleansing at index colonoscopy will likely have financial benefits in Italy, Spain and the UK. A paucity of data, for France and Germany, limits the robustness of conclusions in these countries.

Quality measures improving endoscopic screening of colorectal cancer: a review of the literature

INTRODUCTION

Colorectal cancer (CRC) is a major health-care problem all over the world and CRC screening is effective in reducing mortality and increasing the 5-year survival. Colonoscopy has a central role in CRC screening. It can be performed as a primary test, as a recall policy after a positive result of another screening test, and for surveillance. Since effectiveness of endoscopic screening depends on adequate detection and removal of colonic polyps, consistent quality measures, which are useful in enhancing the diagnostic yield of examination, are essential. Areas covered: The aim of this review is to analyze current evidence from literature supporting quality measures able to refine endoscopic screening of colorectal cancer. Expert commentary: Quality measures namely a) time slot allotted to colonoscopy, b) assessment of indication, c) bowel preparation, d) Cecal intubation, e) withdrawal time, f) adenoma detection rate, g) proper management of lesions (polypectomy technique, polyps retrieval rate and tattooing of resection sites), and h) adequate follow-up intervals play a key role in identifying malignant and at-risk lesions and improving the outcome of screening. Adherence to these quality measures is critical to maximize the effectiveness of CRC screening, as well as, a proper technique of colonoscopy and a quality report of the procedure. Among all recommended measures, adenoma detection rate is the most important and must be kept above the recommended quality threshold by all physicians practicing in the setting of screening.

Impact of high-volume, intermediate-volume and low-volume bowel preparation on colonoscopy quality and patient satisfaction: An observational study

Background

Although optimal bowel preparation is essential for high-quality screening colonoscopy, documentation of preparation quality, patient satisfaction and adherence is scarce.

Aim

The aim of this article is to compare low-volume (LV, 300 ml sodium picosulfate), intermediate-volume (IV, 2 l polyethylene glycol, PEG + ascorbic acid and sodium ascorbate), and high-volume (HV, 4 l PEG) purgatives.

Results

A total of 5000 individuals (50.5% women) were enrolled between March 2015 and July 2017 (LV:IV:HV = 3.61:1.54:1). Overall sex- and age-adjusted adenoma detection rate was 25.4% (LV 23.8%, IV 25.4%, HV 29.8%), median age was 59.6 years, and cleansing was successful in 96.8%. Success rates of bowel cleansing were highest with HV (97.6%), followed by LV (97.2%) and IV (95.3%) with OR 2.04 (CI 95% 1.20-3.45, p = 0.008) and OR 1.79 (CI 95% 1.27-2.50, p = 0.001), respectively, compared to IV. A total of 93.5% of the LV group would use the same purgative in the future, 73.2% of IV and 69.4% of HV. A total of 84.4% would prefer overnight preparation, 12.1% same-day preparation.

Conclusion

All purgatives investigated showed good bowel cleansing quality results, patient satisfaction and compliance. Improvement in patient information might lead to even higher participation rates in screening colonoscopy since one in five patients stated that bowel preparation worried him or her most prior to colonoscopy.

Colonoscopy quality requisites for selecting surveillance intervals: A World Endoscopy Organization Delphi Recommendation

BACKGROUND AND AIMS

Different post-polypectomy guidelines underscore the need for high-quality baseline colonoscopy before appropriate surveillance recommendations can be made. Standards for colonoscopy practice have been advocated by gastrointestinal societies. Our aims were to define standards for the procedural practice of colonoscopy in this particular setting of surveillance and to generate a colonoscopy procedural quality checklist that could be implemented in clinical practice.

METHODS

This study was based on the Delphi process methodology. The baseline questionnaire included 12 domains and 56 individual statements. A total of three rounds were carried out between September 2015 and March 2016 until consensus or lack of consensus was reached.

RESULTS

In total, consensus was reached on 27 statements in nine domains. High levels of agreement and consensus were reached that: (i) colonoscopy should be considered complete only if the whole cecum has been inspected, including the ileocecal valve and the appendiceal orifice (agreement score 4.63; degree of consensus 82%); (ii) quality of the bowel preparation should always be reported (agreement score 4.9, degree of consensus 94%); and (iii) it is preferable to use a segmental validated scale (agreement score 4.36, degree of consensus 86%). Consensus was also reached regarding multiple statements related to documentation of polyps and their resection. Finally, a colonoscopy quality checklist was drafted.

CONCLUSION

Consensus on different statements regarding quality of colonoscopy has been reached. Based on this consensus, we propose a colonoscopy quality checklist that would be helpful for post-polypectomy surveillance recommendations.

Assessment of bowel cleansing quality in colon capsule endoscopy using machine learning: a pilot study

BACKGROUND AND STUDY AIMS

 The aim of this study was to develop a machine learning-based model to classify bowel cleansing quality and to test this model in comparison to a pixel analysis model and assessments by four colon capsule endoscopy (CCE) readers.

METHODS

 A pixel analysis and a machine learning-based model with four cleanliness classes (unacceptable, poor, fair and good) were developed to classify CCE videos. Cleansing assessments by four CCE readers in 41 videos from a previous study were compared to the results both models yielded in this pilot study.

RESULTS

 The machine learning-based model classified 47 % of the videos in agreement with the averaged classification by CCE readers, as compared to 32 % by the pixel analysis model. A difference of more than one class was detected in 12 % of the videos by the machine learning-based model and in 32 % by the pixel analysis model, as the latter tended to overestimate cleansing quality. A specific analysis of unacceptable videos found that the pixel analysis model classified almost all of them as fair or good, whereas the machine learning-based model identified five out of 11 videos in agreement with at least one CCE reader as unacceptable.

CONCLUSIONS

 The machine learning-based model was superior to the pixel analysis in classifying bowel cleansing quality, due to a higher sensitivity to unacceptable and poor cleansing quality. The machine learning-based model can be further improved by coming to a consensus on how to classify cleanliness of a complete CCE video, by means of an expert panel.

Bowel preparation quality scales for colonoscopy

Colorectal cancer (CRC) is the third most common cancer and second leading cause of cancer-related death in the United States. Colonoscopy is widely preferred for CRC screening and is the most commonly used method in the United States. Adequate bowel preparation is essential for successful colonoscopy CRC screening. However, up to one-quarter of colonoscopies are associated with inadequate bowel preparation, which may result in reduced polyp and adenoma detection rates, unsuccessful screens, and an increased likelihood of repeat procedure. In addition, standardized criteria and assessment scales for bowel preparation quality are lacking. While several bowel preparation quality scales are referred to in the literature, these differ greatly in grading methodology and categorization criteria. Published reliability and validity data are available for five bowel preparation quality assessment scales, which vary in several key attributes. However, clinicians and researchers continue to use a variety of bowel preparation quality measures, including nonvalidated scales, leading to potential confusion and difficulty when comparing quality results among clinicians and across clinical trials. Optimal clinical criteria for bowel preparation quality remain controversial. The use of validated bowel preparation quality scales with stringent but simple scoring criteria would help clarify clinical trial data as well as the performance of colonoscopy in clinical practice related to quality measurements.

Bowel preparation quality scales for colonoscopy

Colorectal cancer (CRC) is the third most common cancer and second leading cause of cancer-related death in the United States. Colonoscopy is widely preferred for CRC screening and is the most commonly used method in the United States. Adequate bowel preparation is essential for successful colonoscopy CRC screening. However, up to one-quarter of colonoscopies are associated with inadequate bowel preparation, which may result in reduced polyp and adenoma detection rates, unsuccessful screens, and an increased likelihood of repeat procedure. In addition, standardized criteria and assessment scales for bowel preparation quality are lacking. While several bowel preparation quality scales are referred to in the literature, these differ greatly in grading methodology and categorization criteria. Published reliability and validity data are available for five bowel preparation quality assessment scales, which vary in several key attributes. However, clinicians and researchers continue to use a variety of bowel preparation quality measures, including nonvalidated scales, leading to potential confusion and difficulty when comparing quality results among clinicians and across clinical trials. Optimal clinical criteria for bowel preparation quality remain controversial. The use of validated bowel preparation quality scales with stringent but simple scoring criteria would help clarify clinical trial data as well as the performance of colonoscopy in clinical practice related to quality measurements.

Split-dose 4-L polyethylene glycol regimen for patients with previous colorectal surgery in bowel preparation before colonoscopy: A randomized, controlled, single-blind study

OBJECTIVE

We aimed to investigate the efficacy of a split-dose 4-L polyethylene glycol (PEG) regimen for the quality of bowel preparation in Asian patients with previous colorectal surgery for colorectal cancer (CRC).

METHODS

This was a prospective, single-center, randomized controlled, endoscopist-blinded study. Patients with previous colorectal surgery for CRC were randomly allocated to a routine, morning-only 2-L PEG (2-MO) group or a split-dose 4-L PEG (4-SD) group. The primary outcome was a successful bowel preparation rate. Secondary outcomes were polyp detection rate (PDR), adenoma detection rate (ADR), patient compliance, satisfaction, tolerance, willingness to repeat the preparation and difficulty of the bowel preparation process.

RESULTS

In total, 187 patients were included (93 in the 2-MO group, 94 in the 4-SD group) in this study. The rate of successful bowel preparation in the 4-SD group was higher than in the 2-MO group (89.4% vs 66.7%, P < 0.001) in an intention-to-treat analysis according to the Aronchick score. Patients' satisfaction with the bowel preparation process in the 4-SD group was superior to that in the 2-MO group (93.4% vs 82.2%, P = 0.021). No significant differences were detected in PDR, ADR, patient compliance, tolerance, willingness to repeat the preparation or difficulty of the bowel preparation process.

CONCLUSIONS

The 4-SD PEG regimen was superior to a routine, morning-only 2-L PEG preparation for bowel preparation in an Asian population with previous colorectal surgery.

Novel 1 L polyethylene glycol-based bowel preparation NER1006 for overall and right-sided colon cleansing: a randomized controlled phase 3 trial versus trisulfate

BACKGROUND AND AIMS

NER1006 is the first 32 fluid ounce (1 L) polyethylene glycol-based bowel preparation. This randomized, multicenter, colonoscopist/central reader-blinded phase 3 non-inferiority trial assessed the efficacy, safety, and tolerability of NER1006 versus trisulfate for bowel cleansing.

METHODS

Patients undergoing colonoscopy were randomized (1:1) to receive NER1006 or trisulfate, using evening/morning split-dosing administration. Blinded central readers used the validated Harefield Cleansing Scale to evaluate 2 alternative primary endpoints: overall bowel-cleansing success and high-quality cleansing of the ascending colon/cecum. Secondary endpoints included lesion detection, Boston Bowel Preparation Scale (BBPS) assessment, and adherence. The non-inferiority margin was 10% and the significance threshold was P < .025.

RESULTS

Of 621 patients randomized (NER1006, n=310; trisulfate, n=311), 556 were evaluated for efficacy (NER1006, n=276; trisulfate, n=280). NER1006 achieved non-inferiority versus trisulfate for both primary endpoints of overall bowel-cleansing success (85.1% vs 85.0%; difference, 0.14%; one-sided 97.5% lower confidence limit [LCL], -8.15%; P = .528) and high-quality cleansing of the ascending colon/cecum (35.9% versus 29.3%; difference, 6.58%; LCL, -1.69%; P = .059). BBPS assessments supported overall bowel-cleansing success rates. Lesion detection rates were similar between the groups. The percentage of patients with treatment-related adverse events was 14.9% with NER1006 and 9.4% with trisulfate. Both bowel preparations showed similar overall tolerability and safety profiles. Adherence was very high in both arms.

CONCLUSIONS

With evening/morning split dosing, NER1006 was as effective as trisulfate for overall bowel and right-sided colon cleansing. Adverse event rates were slightly higher with NER1006 than trisulfate, but did not compromise tolerability, adherence, or efficacy. (Clinical trial registration number: NCT02254486.).

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

BACKGROUND & AIMS

Some features of patients are associated with inadequate bowel preparation, which reduces the effectiveness of colonoscopy examination. We performed a systematic review and meta-analysis of the association between patients' sociodemographic characteristics, health conditions, and medications with inadequate bowel preparation.

METHODS

We searched the PubMed, Scopus, and Cochrane Review databases for randomized controlled trials cohort (prospective and retrospective), case-control, and cross-sectional studies published through March 2016. We collected information on study design, study population, and bowel preparation. For each factor, we obtained the odds ratio (OR) for inadequate bowel preparation. We conducted the meta-analyses using the random-effects approach and investigated any identified heterogeneity and publication bias via graphical methods, stratification, and meta-regression.

RESULTS

We performed a meta-analysis of 67 studies, comprising 75,818 patients. The estimated pooled OR for inadequate bowel preparation was small for sociodemographic characteristics: 1.14 for age, and 1.23 for male sex (excluding studies in Asia, which had substantial heterogeneity and publication bias), and 1.49 for low education. The effect of high body mass index differed significantly in studies with mostly female patients (OR, 1.05) vs those with mostly male patients (OR, 1.30) (P = .013 for the difference). ORs for constipation and cirrhosis were heterogeneous; adjusted ORs were larger than unadjusted ORs (1.97 vs 1.29 for constipation and 3.41 vs 1.36 for cirrhosis). Diabetes (OR, 1.79), hypertension (OR, 1.25), stroke or dementia (OR, 2.09), and opioid use (OR, 1.70) were associated with inadequate bowel preparation. History of abdominal surgery (OR, 0.99) did not associate with inadequate bowel preparation. Use of tricyclic antidepressants had a larger effect on risk of inadequate bowel preparation in studies of mostly female patients (OR, 2.62) than studies of mostly male patients (OR, 1.42) (P = .085 for the difference).

CONCLUSIONS

In a systematic review and meta-analysis, we found no single patient-related factor to be solely associated with inadequate bowel preparation. Health conditions and use of some medications appear to be stronger predictors than sociodemographic characteristics.

Validating bowel preparation scales

BACKGROUND AND STUDY AIM

 Few scales assessing bowel preparation quality have been validated, and direct between-scale comparisons remain scarce. The aim of the study was to compare inter- and intra-rater reliability, predictive abilities for clinical outcomes, and ease of use for each scale.

METHODS

 Colonoscopy video recordings highlighting five colonic segments after washing were viewed independently by three physicians, and cleanliness was evaluated using the Boston Bowel Preparation Scale (BBPS), the Chicago Bowel Preparation Scale (CBPS), and the Harefield Cleansing Scale (HCS) in randomized order. Kappa or intraclass correlations quantified intra- and inter-rater reliability. Ease of use was evaluated (1 - 10 scale, 1 = easy), as were associations between scores, adenoma detection, and adequacy of preparation to exclude lesions ≥ 5 mm.

RESULTS

 Among 83 colonoscopy videos, indications included screening or surveillance in 72.3 %. Mean (± SD) scores of the respective three raters were 5.17 ± 1.57, 6.49 ± 1.48, and 5.12 ± 1.21 for BBPS, and 23.73 ± 6.01, 28.39 ± 5.47, and 24.75 ± 5.83 for CBPS, while successful HCS scores (grade A or B) were given for 76 %, 89 %, and 63 % of examinations. Intra-rater reliability ranges were 0.88 - 1.00, 0.83 - 1.00, and 0.62 - 1.00 for BBPS, CBPS, and HCS, respectively. Similarly, inter-rater reliability ranges were 0.50 - 0.79, 0.64 - 0.83, and 0.28 - 0.52, respectively. Sources of disagreement included varying rater strictness, which was possibly most marked for preparations rated as intermediate. Overall, associations between preparation scores and adenoma detection lacked statistical significance.

CONCLUSION

 The BBPS and CBPS showed the best inter- and intra-rater reliability, and the BBPS was considered the easiest to use. Further studies are needed to determine an optimal adequacy threshold for these scales, with the goal of predicting clinical outcomes and determining the appropriate interval to the next colonoscopy.

Split-dose preparation for colonoscopy increases adenoma detection rate: a randomised controlled trial in an organised screening programme

OBJECTIVE

Although a split regimen of bowel preparation has been associated with higher levels of bowel cleansing, it is still uncertain whether it has a favourable effect on the adenoma detection rate (ADR). The present study was aimed at evaluating whether a split regimen was superior to the traditional 'full-dose, day-before' regimen in terms of ADR.

DESIGN

In a multicentre, randomised, endoscopist-blinded study, 50-69-year-old subjects undergoing first colonoscopy after positive-faecal immunochemical test within an organised colorectal cancer organised screening programmes were 1:1 randomised to receive low-volume 2-L polyethylene glycol (PEG)-ascorbate solution in a 'split-dose' (Split-Dose Group, SDG) or 'day-before' regimen (Day-Before Group, DBG). The primary endpoint was the proportion of subjects with at least one adenoma. Secondary endpoints were the detection rates of advanced adenomas and serrated lesions at per-patient analysis and the total number of lesions.

RESULTS

690 subjects were included in the study. At per-patient analysis, the proportion of subjects with at least one adenoma was significantly higher in the SDG than in the DBG (183/345, 53.0% vs 141/345, 40.9%, relative risk (RR) 1.22, 95% CI 1.03 to 1.46); corresponding figures for advanced adenomas were 26.4% (91/345) versus 20.0% (69/345, RR 1.35, 95% CI 1.06 to 1.73). At per-polyp analysis, the total numbers of both adenomas and advanced adenomas per subject were significantly higher in the SDG (1.15 vs 0.8, p <0.001; 0.36 vs 0.22, p<0.001).

CONCLUSIONS

In an organised screening setting, the adoption of a split regimen resulted into a higher detection rate of clinically relevant neoplastic lesions, thus improving the effectiveness of colonoscopy. Based on such evidence, the adoption of a split regimen for colonoscopy should be strongly recommended.

CLINICAL TRIAL REGISTRATION NUMBER

NCT02178033.

Enhanced instructions improve the quality of bowel preparation for colonoscopy: a meta-analysis of randomized controlled trials

BACKGROUND AND AIMS

The success of a colonoscopy is highly dependent on the quality of bowel preparation (BP). Many patients have poor BP due to non-compliance with regular instructions. Reports concerning the effects of enhanced instructions on BP quality are inconsistent. The aim of this meta-analysis was to compare BP quality between patients receiving enhanced instructions in addition to regular instructions and those who received regular instructions only.

METHODS

MEDLINE, EMBASE, Web of Science, and the Cochrane Library were searched to identify relevant studies published for August 2015. The quality of BP (adequate/inadequate), adenoma detection rate, polyp detection rate, willingness to repeat preparation, and adverse events were estimated by using odds ratios (OR) and 95% confidence intervals (CI) with random effects models.

RESULTS

Eight randomized controlled trials (n = 3795) were included. Patients who received enhanced instructions showed significantly better BP quality than those receiving only regular instructions (OR, 2.35; 95% CI, 1.65-3.35; P < .001). Subgroup analysis showed that the beneficial effects of enhanced instructions on BP quality were consistent among patients receiving different purgative types, administration methods, or diet restriction (all P < .05). Patients in the enhanced instructions group showed more willingness to repeat the preparation (OR, 1.91; 95% CI, 1.20-3.04; P = .006).

CONCLUSIONS

Enhanced instructions significantly improved the quality of BP and willingness to repeat the preparation in patients undergoing colonoscopy. Factors related to patient instructions appear to be as important as the preparation method itself in improving BP quality.

UK key performance indicators and quality assurance standards for colonoscopy

Colonoscopy should be delivered by endoscopists performing high quality procedures. The British Society of Gastroenterology, the UK Joint Advisory Group on GI Endoscopy, and the Association of Coloproctology of Great Britain and Ireland have developed quality assurance measures and key performance indicators for the delivery of colonoscopy within the UK. This document sets minimal standards for delivery of procedures along with aspirational targets that all endoscopists should aim for.

Expert opinions and scientific evidence for colonoscopy key performance indicators

Colonoscopy is a widely performed procedure with procedural volumes increasing annually throughout the world. Many procedures are now performed as part of colorectal cancer screening programmes. Colonoscopy should be of high quality and measures of this quality should be evidence based. New UK key performance indicators and quality assurance standards have been developed by a working group with consensus agreement on each standard reached. This paper reviews the scientific basis for each of the quality measures published in the UK standards.

Randomised clinical study comparing the effectiveness and physiological effects of hypertonic and isotonic polyethylene glycol solutions for bowel cleansing

Objectives

Bowel cleansing is necessary before colonoscopy, but is a burden to patients because of the long cleansing time and large dose volume. A low-volume (2 L) hypertonic polyethylene glycol-ascorbic acid solution (PEG-Asc) has been introduced, but its possible dehydration effects have not been quantitatively studied. We compared the efficacy and safety including the dehydration risk between hypertonic PEG-Asc and isotonic PEG regimens.

Design

This was an observer-blinded randomised study. Participants (n=310) were allocated to receive 1 of 3 regimens on the day of colonoscopy: PEG-Asc (1.5 L) and water (0.75 L) dosed with 1 split (PEG-Asc-S) or 4 splits (PEG-Asc-M), or PEG-electrolyte solution (PEG-ES; 2.25 L) dosed with no split. Dehydration was analysed by measuring haematocrit (Ht).

Results

The cleansing time using the hypertonic PEG-Asc-S (3.33±0.48 hours) was significantly longer than that with isotonic PEG-ES (3.05±0.56 hours; p<0.001). PEG-Asc-M (3.00±0.53 hours) did not have this same disadvantage. Successful cleansing was achieved in more than 94% of participants using each of the 3 regimens. The percentage changes in Ht from baseline (before dosing) to the end of dosing with PEG-Asc-S (3.53±3.32%) and PEG-Asc-M (4.11±3.07%) were significantly greater than that with PEG-ES (1.31±3.01%).

Conclusions

These 3 lower volume regimens were efficacious and had no serious adverse effects. Even patients cleansed with isotonic PEG-ES showed significant physiological dehydration at the end of dosing. The four-split PEG-Asc-M regimen is recommended because of its shorter cleansing time without causing serious nausea.

Trial registration number

UMIN000013103; Results.

Optimizing bowel preparation for colonoscopy: a guide to enhance quality of visualization

Colonoscopy is an important screening and therapeutic modality for colorectal cancer. Unlike other screening tests, colonoscopy is dependent on pre-procedure bowel preparation. If the bowel preparation is poor, significant pathology may be missed. Many factors are known to improve bowel preparation. This review will highlight those factors that may optimize the bowel preparation, including choice of bowel preparation, grading or scoring of the bowel preparation, special factors that influence preparation, and diet prior to colonoscopy that affects bowel preparation. The aim of the review is to offer suggestions and guide endoscopists on how to optimize the bowel preparation for the patients undergoing colonoscopy.

Low-residue versus clear liquid diet before colonoscopy: a meta-analysis of randomized, controlled trials

BACKGROUND AND AIMS

Colonoscopy is extremely important for the identification and removal of precancerous polyps. Bowel preparation before colonoscopy is essential for adequate visualization. Traditionally, patients have been instructed to consume only clear liquids the day before a colonoscopy. However, recent studies have suggested using a low-residue diet, with varying results. We evaluated the outcomes of patients undergoing colonoscopy who consumed a clear liquid diet (CLD) versus low-residue diet (LRD) on the day before colonoscopy by a meta-analysis.

METHODS

Scopus, PubMed/MEDLINE, Cochrane databases, and CINAHL were searched (February 2015). Studies involving adult patients undergoing colonoscopy examination and comparing LRD with CLD on the day before colonoscopy were included. The analysis was conducted by using the Mantel-Haenszel or DerSimonian and Laird models with the odds ratio (OR) to assess adequate bowel preparations, tolerability, willingness to repeat diet and preparation, and adverse effects.

RESULTS

Nine studies (1686 patients) were included. Patients consuming an LRD compared with a CLD demonstrated significantly higher odds of tolerability (OR 1.92; 95% CI, 1.36-2.70; P < .01) and willingness to repeat preparation (OR 1.86; 95% CI, 1.34-2.59; P < .01) with no differences in adequate bowel preparations (OR 1.21; 95% CI, 0.64-2.28; P = .58) or adverse effects (OR 0.88; 95% CI, 0.58-1.35; P = .57).

CONCLUSION

An LRD before colonoscopy resulted in improved tolerability by patients and willingness to repeat preparation with no differences in preparation quality and adverse effects.

Validated Scales for Colon Cleansing: A Systematic Review

OBJECTIVES

Bowel cleanliness is a critical determinant of colonoscopy quality, mandating its standardized assessment, yet bowel preparation scales have been variably validated. The objective of this study was to assess validity and reliability of existing bowel preparation scales.

METHODS

A systematic review of literature from January 1980 to January 2015 was performed. Main outcomes of this study are face, content, construct, and criterion validity, and inter- and intra-observer reliability measured by associations, interclass correlations (ICC) or κ-coefficients.

RESULTS

Fourteen citations assessed seven scales. The Aronchick Scale, showed fair-to-substantial inter-observer reliability (ICC=0.31-0.76), and was the reference for subsequent validity testing. The Ottawa Bowel Preparation Quality Scale revealed superior inter-observer reliability (ICC=0.94). Five studies assessed the Boston Bowel Preparation Scale (BBPS). Increasing BBPS scores were associated with polyp detection (left colon: odds ratio (OR)=2.58 (1.34; 4.98), right colon: OR=1.6 (1.01; 2.55), less repeat colonoscopies (cutoff of 5, P<0.001), and shorter insertion/withdrawal times (P<0.001), while displaying substantial to excellent inter- and intra-observer reliability (ICC=0.74-0.91). Criterion validity of the Harefield Cleansing Scale (HCS) yielded slight-to-moderate expert-investigator agreement (ICC=0.15-0.46); HCS grades were not discriminant for adenoma detection. Inter- and intra-observer reliabilities were fair-to-moderate (ICC=0.46 (0.37; 0.54) and κ=0.28, respectively). The Chicago Bowel Preparation Scale displayed excellent inter-observer reliability (Pearson's r=0.84 (0.79; 0.88)), yet has been less studied.

CONCLUSIONS

To conclude, all the published scales displayed limitations. The BBPS is the most thoroughly validated scale and should be used in a clinical setting. Between-scale comparisons for repeat colonoscopy time interval, ease, and pertinence of use for auditing are needed.

The White Diet is preferred, better tolerated, and non-inferior to a clear-fluid diet for bowel preparation: A randomized controlled trial

BACKGROUND AND AIM

Dietary restrictions contribute to the unpleasantness of bowel preparation for colonoscopy. We compare the effectiveness and tolerability of a low residue diet of white-colored foods ("White Diet") with a clear-fluid diet the day prior to colonoscopy in an endoscopist-blinded randomized non-inferiority trial.

METHODS

Adults undergoing outpatient colonoscopy were randomized with stratification by procedure timing to a White Diet or clear-fluid diet. All received a 2-L polyethylene glycol lavage solution with ascorbate, sodium sulfate, and electrolytes, the day-before for morning and as a split-dose for afternoon procedures. The primary end-point was successful bowel preparation (A or B on the Harefield Cleansing Scale). Regimen tolerance/acceptance was assessed by questionnaire. An intention-to-treat analysis with a predefined non-inferiority margin of 15% was used to compare efficacy.

RESULTS

A total of 226 patients (average age 52 years, 51% male) were randomized (111 clear diet, 115 White Diet). Bowel preparation was successful in 91% on the clear-fluid diet vs 84.4% on the White Diet, difference being -6.6% (lower one sided 95% CI -13.8%), with no difference according to diet. The split-dose regimen (in 55%) had a higher success rate than day-before regimen (96% vs 80%, p < 0.001). The White Diet was preferred with less hunger and interference with daily activities (p < 0.001). Procedural/withdrawal time and polyp/adenoma detection were similar between groups.

CONCLUSIONS

The White Diet was preferred and better tolerated by patients without detriment to the success of bowel preparation or colonoscopy performance, especially with the split-dose regimen.