Bisacodyl plus split 2-L polyethylene glycol-citrate-simethicone improves quality of bowel preparation before screening colonoscopy

The safety and effects of high- and low-volume polyethylene glycol bowel preparation methods before colonoscopy on bowel cleanliness: a systematic review and meta-analysis

Background

Although both high- and low-volume polyethylene glycol (PEG) are widely used in intestinal preparation before colonoscopy, there is still controversy over the superiority of their cleaning effects. This meta-analysis sought to explore the safety and effects of high-volume PEG solution and low-volume PEG mixed solution on intestinal cleanliness before colonoscopy.

Methods

The PubMed, EMBASE, and Cochrane Library databases were searched to retrieve relevant articles on the effects of high- and low-volume PEG mixture solutions on intestinal cleanliness from the inception of the databases to October 15, 2022. Two independent researchers screened the literature according to the predetermined inclusion and exclusion criteria, and extracted the required data separately. A bias risk assessment was conducted for each study using the relevant tools in the Cochrane Handbook. The included data were subjected to a meta-analysis using R 4.2.1 software.

Results

This article includes a total of 15 studies involving a total of 5,847 patients. There was no difference in the cleanliness score, qualified rate of intestinal cleanliness and patient compliance between the high- and low-volume group. The patients in the low-volume PEG mixed solution group had a higher repeat willingness bowel cleansing rate than those in the high-volume PEG group [risk ratio (RR) =0.71, 95% confidence interval (CI): 0.62-0.82, P<0.01]. Compared with the low-volume group, the incidence of adverse reactions such as nausea, vomiting, and abdominal pain increased in the high-volume group (RR =1.38, 95% CI: 1.22-1.56, P<0.01; RR =1.79, 95% CI: 1.41-2.27, P<0.01; RR =1.05, 95% CI: 1.01-1.08, P<0.01).

Conclusions

In the pre-colonoscopy preparation method for patients, although the high-volume PEG and low-volume PEG mixed regimen have similar effects on intestinal cleanliness, the low-volume mixed regimen has a higher willingness to repeat and a lower incidence of adverse reactions. In clinical practice, considering patient compliance and safety, a low-volume mixed regimen may be a more optimal option.

Effect of oral simethicone on the quality of colonoscopy: A systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

In this systematic review and meta-analysis, we aimed to investigate the effect of oral simethicone (SIM), an antifoaming agent, on the quality of colonoscopy in terms of bowel preparation quality, adenoma or polyp detection rate (ADR/PDR) and cecal intubation rate (CIR).

METHODS

All randomized controlled trials (RCTs) on the use of SIM during bowel preparation for colonoscopy published up to 17 March 2021 were identified from the PubMed, EMBASE and Cochrane Library databases. Bowel preparation quality, ADR/PDR/CIR, cecal intubation time (CIT), withdrawal time (WT), patients' tolerability, acceptability and volume of foam and bubbles were compared between the SIM and non-SIM groups.

RESULTS

Thirty-eight RCTs with 10 505 patients were included. Oral SIM significantly increased the rate of total Boston bowel preparation scale (BBPS) score ≥6 (risk ratio [RR]  1.13, P < 0.0001), acceptability (RR  1.15, P = 0.01) and the rate of no or minimal foam and bubbles (RR  1.28, P < 0.00001) and decreased abdominal distension (RR  0.64, P < 0.0001). However, it had no significant impact on overall ADR, overall PDR, CIR, CIT or WT. The rate of total BBPS score ≥6 remained significantly higher in the SIM group when a single-dose laxative regimen or a SIM dosage of ≥320 mg was employed; and ADR, PDR and CIR were significantly increased in the SIM group among colonoscopy clinicians who achieved an ADR <31%, PDR <45% and CIR <96%, respectively.

CONCLUSIONS

Oral SIM can improve bowel preparation quality, especially in patients receiving a SIM dosage of ≥320 mg or a single-dose laxative regimen. SIM may be preferred by junior colonoscopy physicians/trainees with a lower ADR/PDR or CIR.

Efficacy of elobixibat as bowel preparation agent for colonoscopy: Prospective, randomized, multi-center study

BACKGROUND AND AIM

Elobixibat is a novel ileal bile acid transporter inhibitor. This study aimed to compare the efficacy, tolerability, and safety of the combination of elobixibat and 1 L of polyethylene glycol formulation containing ascorbic acid (PEG-Asc) solution versus the combination of sodium picosulfate and 1-L PEG-Asc solution as bowel preparation for colonoscopy.

METHODS

This multi-center, randomized, observer-blinded, non-inferiority study recruited 210 outpatients who were assigned to either the elobixibat plus 1-L PEG-Asc group (group A) or the sodium picosulfate plus 1-L PEG-Asc group (group B). The quality of the bowel cleansing level was assessed by the Boston Bowel Preparation Scale (BBPS) and compared the bowel cleansing level between the groups. Data regarding bowel preparation time, patients' tolerability, and adverse events were also analyzed.

RESULTS

Data for 196 patients (99 in group A and 97 in group B) were analyzed finally. BBPS was comparable between group A and B (8.3 ± 0.9 vs. 8.3 ± 0.7; P = 0.88). Consequently, the adequate bowel preparation rate in groups A and B was 95.0% and 99.0%, respectively (-4.0%, 95% CI -9.3 to 1.5). Bowel preparation time in group A was similar to that in group B (348.2 ± 79.8 min vs. 330.8 ± 82.5 min; P = 0.13), whereas, sleep disturbance was significantly less frequent in group A than in group B (10.2% vs. 22.7%; P = 0.02).

CONCLUSIONS

The combination of elobixibat and 1-L PEG-Asc can be considered an alternative bowel preparation for colonoscopy considering the equivalent bowel cleansing effect and less frequent sleep disturbance. The Japan Registry of Clinical Trials (jRCTs41180026).

Volume of fluid consumption during preparation for colonoscopy is possibly the single most important determinant of bowel preparation adequacy

Background

The effectiveness and safety of colonoscopy are directly dependent on the quality of bowel preparation. Multiple risk factors for inadequate bowel preparation (IBP) have been identified; however, IBP is still reported in 20-30% of cases in most studies. We aimed to identify modifiable predictors of the adequacy of bowel preparation using sodium picosulfate, and to recommend easily modifiable parameters to increase the success rate of colonoscopies.

Methods

This was a single-center observational study of adult outpatients referred for an elective colonoscopy. Patients were interviewed prior to colonoscopy; volume of liquids consumed was calculated as number of 200-mL cups showed to the patient. Additional information, including medical history, diagnoses and regular medications, was procured from patients’ medical records. Univariate and multivariate regression analyses were performed to identify factors significantly associated with IBP in a subgroup analysis of high-risk patients.

Results

The rate of IBP in 1172 subjects was 19.4%. This rate decreased as fluid consumption increased, with a further drop associated with shorter intervals from end of preparation to colonoscopy. Drinking < 1.4 L significantly increased the risk of IBP (odds ratio [OR] 3.62, 95% confidence interval [CI] 2.65-4.95), while drinking ≥2 L was associated with adequate preparation (OR 0.09, 95%CI 0-0.42). These associations were stronger in high-risk individuals.

Conclusion

Greater fluid intake and short interval to colonoscopy are easily modifiable parameters that can substantially reduce the rate of IBP, especially among high-risk individuals.

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.

Effect of antifoaming agent on benign colorectal tumors in colonoscopy: A meta-analysis

BACKGROUND

Although several trials have shown that the addition of antifoaming agents to polyethylene glycol (PEG) can improve bowel preparation, whether PEG plus antifoaming agents have a beneficial role in the detection of benign tumors during colonoscopy has yet to be confirmed. Our aim was to clarify whether adding simethicone to PEG solution could improve the detection of benign colorectal tumors.

AIM

To clarify whether adding simethicone to PEG solution could improve the detection of benign colorectal tumors.

METHODS

The PubMed, EMBASE, and Cochrane Library databases were searched for articles published prior to September 2019. The outcomes included the detection rates of colorectal adenomas and polyps.

RESULT

Twenty studies were eligible. Although there was no difference in the colorectal adenoma detection rate (ADR), a significant effect of simethicone for diminutive adenomas (< 10 mm) was revealed in the group taking simethicone. We also found that simethicone could significantly improve the ADR in the proximal colon but did not affect the colorectal polyp detection rate. Furthermore, the subgroup analyses revealed a beneficial effect of simethicone on the ADR among Asians (P = 0.005) and those with an ADR < 25% (P = 0.003). Moreover, it was a significant finding that the low dose simethicone was as effective as the high dose one with respect to the detection of benign colorectal tumors.

CONCLUSION

In summary, the addition of simethicone to PEG might improve the detection of diminutive adenomas in the right colon by colonoscopy in Asia. Low-dose simethicone was recommended for the detection of benign colorectal tumors. However, large clinical trials are necessary to validate our results and determine the ideal dose of simethicone.

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.

Efficacy and Tolerability of Prucalopride in Bowel Preparation for Colonoscopy: A Systematic Review and Meta-Analysis

INTRODUCTION

Adequate bowel preparation is a vital determinant for the success of colonoscopy. However, individuals who undergo bowel preparation for colonoscopy can experience major discomfort. To solve this problem, adding prucalopride to the prepared solution may reduce intake volume, decreasing discomfort and side effects. We performed meta-analyses and systematic review of available randomized controlled trials.

METHODS

Meta-analyses were conducted to evaluate the overall relative risk and 95% confidence intervals in the combined studies for the assessment of primary outcome, which is the efficacy of bowel preparation with the addition of prucalopride.

RESULTS

Four randomized controlled trials involving 581 patients were included. When data were pooled for all patients in two non-inferiority studies, no significant difference in the quality of bowel preparation was observed between patients receiving prucalopride plus bowel preparation solution at a lower volume and those receiving the existing solution (relative risk: 0.94; 95% confidence interval: 0.86-1.03). The effects of prucalopride on acceptability, adverse events, adenoma detection rate, and polyp detection rate did not significantly differ from those of traditional solutions.

CONCLUSIONS

The combination of prucalopride and bowel preparation solution at a lower volume has similar effects on bowel preparation, and its use did not increase the occurrence of adverse effects.

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.

Simethicone decreases bloating and improves bowel preparation effectiveness: a systematic review and meta-analysis

BACKGROUND

Simethicone is an adjunct frequently used during bowel preparation before colonoscopy and currently there is no consensus on whether it should be recommended in standard bowel preparation. We performed a systematic review and meta-analysis to determine the effect simethicone has on bowel cleanliness, adenoma detection rate (ADR), and tolerability.

METHODS

We searched the literature for studies that compared colon cleansing of patients that received standard bowel preparation alone and in combination with simethicone prior to colonoscopy. The primary outcomes were colon cleanliness, ADR, and tolerability.

RESULTS

Sixteen randomized controlled trials with 5630 patients were included in meta-analysis. Overall, polyethylene glycol (PEG) with simethicone improves colon cleansing compared with PEG alone (odds ratio [OR] 1.48, CI 1.11 to 1.97, P = 0.008). This improvement was seen for single dosing (OR 1.83, CI 1.20 to 2.79, P = 0.005) but not for split dosing (OR 1.32, CI 0.72 to 2.43, P = 0.38). Overall, simethicone had no effect on ADR (OR 1.22, CI 0.81 to 1.83, P = 0.33), but in patients receiving single dosing, simethicone significantly increased ADR (OR 1.96, CI 1.22 to 3.16, P = 0.005). The rates of nausea (OR 0.96, CI 0.75 to 1.24, P = 0.75), vomiting (OR 1.00, CI 0.69 to 1.44, P = 0.99), and abdominal pain (OR 0.69, CI 0.40 to 1.18, P = 0.17) were not significantly different between PEG and PEG + simethicone cohorts. For abdominal bloating, the PEG cohort had greater odds of experiencing bloating than the PEG + simethicone cohort (OR 2.33, CI 1.70 to 3.20, P < 0.00001).

CONCLUSIONS

Simethicone improves colon cleanliness and ADR; however, this improvement is not seen in patients receiving split-dose PEG. Furthermore, simethicone decreases abdominal bloating but has no effect on nausea, vomiting, and abdominal pain. Simethicone may be a useful bowel preparation adjunct in patients unable to receive split-dose PEG.

A Randomized Trial of Split Dose 3 L Polyethylene Glycol Lavage Solution, 2 L Polyethylene Glycol Lavage Combined With Castor Oil, and 1 L of Polyethylene Glycol Lavage Solution Combined With Castor Oil and Ascorbic Acid for Preparation for Colonoscopy

Background: Castor oil (CaO) has the potential of halving the required volume of bowel preparation solution; however, no clinical trial investigated the efficacy of CaO on bowel preparation for colonoscopy in addition to polyethylene glycol (PEG).

Objectives: Our aim was to evaluate efficacy and safety of lower dose PEG together with 30 mL CaO alone or plus ascorbic acid (Asc) in bowel preparation before colonoscopy.

Methods: Two hundred and forty-six patients were allocated randomly to ingest 2 L PEG with 30 mL CaO, 1 L PEG with 30 mL CaO plus 5 g Asc, or 3 L PEG. We used Boston Bowel Preparation Scale (BBPS) to evaluate bowel preparation efficacy. We also determined other outcomes such as procedure time, polyp or adenoma detection rate, and adverse events (AEs).

Results: Of 282 patients recruited, 36 were excluded. Groups were matched for baseline characteristics except weight (P = 0.020) and body mass index (BMI) (P = 0.003). Patient's satisfaction was higher in 2 L PEG-CaO (P = 0.016) and 1 L PEG-CaO-Asc groups (P = 0·017). Patients' compliance was 67.5, 71.4, and 80.5% in 3 L PEG, 2 L PEG-CaO, and 1 L PEG-CaO-Asc groups (P = 0.014). Adequate bowel preparation rate was 75, 78.57, and 53.66% in 3 L PEG, 2 L PEG-CaO, and 1 L PEG-CaO-Asc groups (P = 0.021). There were no differences in terms of remaining outcomes.

Conclusions: Despite an increase in patients' satisfaction and compliance, 1 L PEG-CaO-Asc significantly decreased adequate bowel preparation rate. However, 2 L PEG-CaO improved the patients' satisfaction and compliance and increased adequate bowel preparation rate (Registration number, ChiCTR-IIR-17012418).

The role of oral simethicone on the adenoma detection rate and other quality indicators of screening colonoscopy: a randomized, controlled, observer-blinded clinical trial

BACKGROUND AND AIMS

Combining simethicone (SIM) with a colon preparation agent has been shown to improve mucosal visibility during screening colonoscopy, but its effect on the adenoma detection rate (ADR) remains unclear. SIM is commonly used through the endoscope to eliminate bubbles during endoscopy. However, this practice recently has been associated with endoscope-transmitted infections. Our aims were to determine the role of SIM added to a polyethylene glycol preparation on the ADR, procedure times, colon preparation, and intraprocedural use of SIM.

METHODS

This was a randomized, controlled, observer-blinded, clinical trial of patients undergoing screening colonoscopy. Patients with a high risk of colorectal cancer were excluded. Patients were randomly assigned to 2 different preparations: polyethylene glycol plus SIM or polyethylene glycol. Two endoscopists blinded to patient preparation regimens scored its quality by using the Boston Bowel Preparation scale (BBPS) and the bubble scale. Interobserver agreement was calculated. The polyp detection rate, ADR, intraprocedural use of SIM, cecal intubation time, and withdrawal time were recorded. For study purposes, cecal intubation time and withdrawal time were combined to determine the effective procedure time.

RESULTS

No significant difference between the polyethylene glycol plus SIM and polyethylene glycol arms was seen regarding the ADR (33.3% vs 38.8%; P = .881) and effective procedure time (759.3 ± 253.1 seconds vs 800.2 ± 459.6 seconds; P = .373), respectively. Intraprocedural use of SIM as well as the bubble scale score were significantly lower in the polyethylene glycol plus SIM arm (1.6% vs 48.9%; P ≤ .05) and (0.1 vs 2.1; P ≤ .05), respectively. Conversely, no difference was found in the BBPS scores. The interobserver agreement for both scores was strong (bubble scale score kappa = .537; P < .05; BBPS score kappa = .184; P <.05).

CONCLUSION

Adding SIM to a polyethylene glycol preparation did not improve the ADR or effective procedure time. Nevertheless, it resulted in lower bubble scale scores, and more importantly, in less intraprocedural use of SIM. This simple and inexpensive intervention may have the potential to reduce the risk of endoscope-transmitted infections. (Clinical trial registration number: NCT03119168.).

Comparison of asymmetric (low morning-dose) and standard split-dose regimen of PEG plus bisacodyl for bowel preparation: A randomized controlled trial

BACKGROUND

Reducing the morning dose of PEG solution may be a reliable strategy to improve the patient compliance of split-dose regimens without affecting efficacy of bowel cleansing.

AIMS

to compare the efficacy for bowel cleansing of an asymmetric split-dose regimen (25% of the dose on the day of colonoscopy and 75% on the day before) with the standard split-dose regimen.

METHODS

Outpatients were enrolled in a randomized, single-blind, non-inferiority clinical trial. All subjects received a split-dose preparation with a 2L PEG-citrate-simethicone plus Bisacodyl. Patients were randomly assigned to: group A, asymmetric split-dose regimen; group B, symmetric split-dose regimen. Primary endpoint was the proportion of adequate bowel cleansing.

RESULTS

Split-dose was taken by 81 and 80 patients in group A and B. Adequate bowel cleansing was achieved in 92.6% and 92.5% patients in group A and B (p = 1.000). No differences were observed regarding Boston Bowel Preparation Scale total score, adenoma detection rate and scores of each colon segment.

CONCLUSIONS

The reduction of morning dose of PEG in a split-dose regimen is not inferior to the standard split-dose regimen in achieving an adequate bowel cleansing. However, further studies are needed to evaluate whether asymmetric preparation is associated to a higher tolerability compared to symmetric split-dose regimen. (NCT03146052).

The benefit of adding oral simethicone in bowel preparation regimen for the detection of colon adenoma: A systematic review and meta-analysis

BACKGROUND AND AIM

Simethicone is an anti-foaming agent commonly used during colonoscopy. Although several randomized trials have shown that oral simethicone in the bowel preparation regimen may improve bowel cleanness, whether it improves adenoma detection rate (ADR) or polyp detection rate remains undetermined. The aim of this study was to determine if oral simethicone in bowel preparation regimen before colonoscopy improves the ADR.

METHODS

A comprehensive literature review was conducted using PubMed, SDOL, Cochrane Library, and ProQuest databases through December 2017. Randomized controlled trials that compared bowel preparation regimens with simethicone versus those without it were included. Effect estimates from each study were extracted and underwent meta-analysis using appropriate models. The primary outcomes were ADR and polyp detection rate, and secondary outcomes included bowel preparation, bubble score, and withdrawal time.

RESULTS

Twelve published randomized controlled studies with 6003 participants were included for meta-analysis. There was no difference in the overall ADR (pooled risk ratio = 1.06, 95% confidence interval = 0.91-1.24) and right-side ADR (risk ratio = 1.50, 95% confidence interval = 0.82-2.75) between the groups with or without simethicone. However, the addition of simethicone improved adenoma detected per patient (2.20 ± 1.36 vs 1.63 ± 0.89) according to one of the included studies. Meta-regression revealed that the baseline ADR < 25% of the included studies was associated with significant benefit of oral simethicone; the number needed to treat was 15.

CONCLUSIONS

The adjunction of oral simethicone significantly improved bowel preparation quality and might benefit adenoma detection in specific settings with low baseline ADR.

Effect of supplemental simethicone for bowel preparation on adenoma detection during colonoscopy: A meta-analysis of randomized controlled trials

BACKGROUND AND AIM

Although several randomized controlled trials (RCTs) have reported that supplemental simethicone (SIM) can improve bowel preparation based on polyethylene glycol, there is no consensus as to whether SIM can ultimately increase the adenoma detection rate (ADR) during colonoscopy. A meta-analysis was performed to assess the effect of SIM on ADR during colonoscopy.

METHODS

Databases including PubMed, EMBASE, and the Cochrane Library were searched to find relevant RCTs. RCTs evaluating the effect of pre-procedure SIM on the ADR during colonoscopy were finally included, and fixed effect models were applied.

RESULTS

Six trials involving 1855 patients were finally included. The present meta-analysis suggested that the ADR during colonoscopy was significantly increased by supplemental SIM (27.9% vs 23.3%, P = 0.02), with a relative risk of 1.20 (95% confidence interval 1.03-1.39). Subgroup analysis suggested that supplemental SIM may be more useful to improve ADR during colonoscopy in endoscopic centers with low baseline ADR.

CONCLUSIONS

Supplemental SIM for bowel preparation based on polyethylene glycol is useful to improve the ADR during colonoscopy.

A randomized controlled trial comparing the efficacy of 1-L polyethylene glycol solution with ascorbic acid plus prucalopride versus 2-L polyethylene glycol solution with ascorbic acid for bowel preparation

OBJECTIVES

Bowel cleansing is a major patient complaint during colonoscopy. Adding laxatives to the bowel preparation is effective in replacing a portion of bowel preparation solution and reducing its volume. Prucalopride is a serotonin receptor agonist that stimulates gastrointestinal motility and provides propulsive force for defecation. This study aimed to compare 1 L polyethylene glycol (PEG) with ascorbic acid (Asc) plus 2 mg prucalopride (1LP/AP) and 2 L PEG with Asc (2LP/A) for colonoscopy preparation with respect to bowel-cleansing quality and side effects.

METHODS

A single-center, randomized, prospective study was conducted with 260 outpatients administered either 1LP/AP or 2LP/A. The primary endpoint was bowel preparation quality, which was evaluated using the Boston Bowel Preparation Scale and Aronchick Bowel Preparation Scale, and the secondary endpoints were patient tolerability and acceptability, assessed by a questionnaire-based survey.

RESULTS

The adequate bowel preparation rates were 88.5% and 83.1% in the 2LP/A and 1LP/AP groups, respectively, and the efficacy of 1LP/AP was equivalent to the control regimen (p=.216). Other colonoscopic variables including adenoma detection rate were similar in both groups. Patient tolerability and acceptability were not significantly different, but patients in the 1LP/AP group were more willing to repeat the same regimen (p=.039).

CONCLUSIONS

Bowel preparation quality with 1LP/AP was equivalent to that with 2LP/A, which did not increase the occurrence of side effects, but it reduced the volume of the solution ingested, and increased patient satisfaction.

Polyethylene glycol plus bisacodyl: A safe, cheap, and effective regimen for colonoscopy in the South Asian patients

Background and Aim

Data regarding the comparison of colonoscopic preparation regimens are still variable. We aimed to assess the adequacy and tolerability of two bowel preparation regimens for afternoon colonoscopy.

Methods

In a randomized, investigator‐blinded trial, two preparation regimens [4‐L split‐dose polyethylene glycol‐electrolytes (PEG‐ELS) and 2‐L PEG‐ELS plus bisacodyl) were compared in terms of bowel cleansing efficacy and adverse effects.

Results

The mean (±SD) age (years) of the 4‐L split‐dose PEG‐ELS group (N = 147) and the 2‐L PEG‐ELS plus bisacodyl (N = 155) were 44.09 (±15.62) (M:F : 2:1) and 44.12 years (±15.61) (M:F : 1.7:1), respectively. Percentage of patients with excellent and good preparation was higher in the 4‐L split‐dose PEG‐ELS regimen compared with the 2‐L PEG‐ELS plus bisacodyl regimen (22.44 vs 17.41 and 44.21% vs 36.12%). Percentage of patients with fair and poor preparation was lower in 4‐L split‐dose PEG‐ELS regimen compared with the 2‐L PEG‐ELS plus bisacodyl regimen (21.08% vs 27.74% and 12.24% vs 18.70%). In comparison with the 2‐L PEG‐ELS plus bisacodyl group, the incidences of abdominal pain (11% vs 15%), bloating (9% vs 12.24%), nausea/vomiting (8.38% vs 9.52%), and sleep disturbance (11% vs 12%) were slightly more common in the 4‐L split‐dose PEG‐ELS group. There were no statistically significant differences between the two regimens with regard to bowel cleansing efficacy and adverse events.

Conclusions

The 2‐L PEG‐ELS plus bisacodyl (10 mg) preparation is as efficacious as the 4‐L split‐dose PEG‐ELS regimen for afternoon colonoscopy. Optimal preparation for colonoscopy can be achieved with the 2‐L PEG‐ELS plus bisacodyl regimen with slightly fewer adverse events and lower cost compared to the 4‐L split‐dose PEG‐ELS regimen.

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.

Endoscopy for patients affected by inflammatory bowel disease: bowel preparation and sedation

Endoscopy has a key role in the management of inflammatory bowel disease (IBD). It is helpful in the diagnosis, in case of relapse, refractoriness, before therapeutic changes, after surgery as well as in the assessment of mucosal healing and in the surveillance of colo-rectal cancer. IBD patients are intended to undergo several times the examination during their lifespan. Bowel preparation and sedation highly contribute to high-quality colonoscopy. Areas covered: Few studies addressed preparation and sedation in the field of IBD. In this review, we focused our attention on the available evidences about bowel preparation and sedation in patients with IBD. Expert commentary: In recent years, the goal of medical treatment in IBD is shifting from clinical improvement in symptoms towards mucosal healing. High-quality endoscopy will gain even more importance in the management of IBD. It is important to locate the most effective preparation and the best sedation in patient with IBD to perform a high-quality endoscopy.

Comparison of a split-dose bowel preparation with 2 liters of polyethylene glycol plus ascorbic acid and 1 liter of polyethylene glycol plus ascorbic acid and bisacodyl before colonoscopy

BACKGROUND AND AIMS

Recently, a low-volume polyethylene glycol formulation containing ascorbic acid (PEG-Asc) has proven as safe and effective as traditional 4-L PEG solutions for colonoscopy preparation. However, currently available aqueous purgative formulations are poorly tolerated. The aim of this study was to compare a split-dose 2-L PEG-Asc formulation and a 1-L PEG-Asc formulation with bisacodyl (10 mg) to determine the quality of bowel cleansing and patient tolerability.

METHODS

A single-center, randomized, observer-blinded study was performed between May 2015 and September 2015. Two hundred outpatients referred for colonoscopy were prospectively enrolled and assigned to either the split-dose 2-L PEG-Asc group or the 1-L PEG-Asc with bisacodyl 10-mg group. The Boston Bowel Preparation Scale (BBPS) and Aronchick Bowel Preparation Scale (ABPS) were used to evaluate bowel cleansing. The tolerability of the regimens and satisfaction of patients was determined based on a questionnaire.

RESULTS

Two hundred patients received either 2-L PEG-Asc or 1-L PEG-Asc with bisacodyl. Regarding colon cleansing outcome (BBPS and ABPS), the 1-L PEG-Asc with bisacodyl group showed similar but non-inferior results compared with the 2-L PEG-Asc group on both BBPS (6.92 ± 1.63 vs 6.57 ± 1.37; P = .103) and ABPS (96% vs 95%; P = 1.000) scales. Tolerability was similar for both 1-L PEG-Asc with bisacodyl and 2-L PEG-Asc.

CONCLUSIONS

1-L PEG-Asc is a suitable alternative to low-volume bowel preparation for colonoscopy. Our study showed that the 1-L PEG-Asc plus bisacodyl preparation has comparable tolerability and results in adequate colon cleansing. Bowel preparation with bisacodyl and 1-L PEG-Asc is a suitable alternative to low-volume bowel preparation for colonoscopy. (Clinical trial registration number: NCT02980562.).

Evaluation of Clensia®, a new low-volume PEG bowel preparation in colonoscopy: Multicentre randomized controlled trial versus 4L PEG

BACKGROUND

Success of colonoscopy is linked to the adequacy of bowel cleansing. Polyethylene glycol 4L (PEG 4L) solutions are widely used for colonic cleansing but with limitations concerning tolerability and acceptability.

AIM

To demonstrate the equivalence of a new low-volume PEG containing citrates and simeticone (Clensia) versus a standard PEG 4L.

METHODS

In this, multicentre, randomised, observer-blind trial, patients received either Clensia 2L or PEG 4L solution. Primary endpoint was the proportion of patients with colon cleansing evaluated as excellent or good.

RESULTS

422 patients received Clensia (n=213) or PEG 4L (n=209). Rate of excellent/good bowel cleansing was 73.6% and 72.3% in Clensia and PEG 4L group respectively. Clensia was demonstrated to be equivalent to PEG 4L. No SAEs were observed. Clensia showed better gastrointestinal tolerability (37.0% vs 25.4%). The acceptability was significantly better with Clensia in terms of proportion of subjects who felt no distress (Clensia 72.8% vs PEG 4L 63%, P=0.0314) and willingness-to-repeat (93.9% vs 82.2%, P=0.0002). The rate of optimal compliance was similar with both formulations (91.1% for Clensia vs 90.9% for PEG 4L, P=0.9388).

CONCLUSIONS

The low-volume Clensia is equally effective and safe in bowel cleansing compared to the standard PEG 4L, with better gastrointestinal tolerability and acceptability.

Combination could be another tool for bowel preparation?

Optimal bowel preparation increases the cecal intubation rate and detection of neoplastic lesions while decreasing the procedural time and procedural-related complications. Although high-volume polyethylene glycol (PEG) solution is the most frequently used preparation for bowel cleansing, patients are often unwilling to take PEG solution due to its large volume, poor palatability, and high incidence of adverse events, such as abdominal bloating and nausea. Other purgatives include osmotic agents (e.g., sodium phosphate, magnesium citrate, and sodium sulfate), stimulant agents (e.g., senna, bisacodyl, and sodium picosulfate), and prokinetic agents (e.g., cisapride, mosapride, and itopride). A combination of PEG with an osmotic, stimulant, or prokinetic agent could effectively reduce the PEG solution volume and increase patients’ adherence. Some such solutions have been found in several published studies to not be inferior to PEG alone in terms of bowel cleansing quality. Although combination methods showed similar efficacy and safety, the value of these studies is limited by shortcomings in study design. New effective and well-tolerated combination preparations are required, in addition to rigorous new validated studies.

Body mass index and quality of bowel preparation: Real life vs. clinical trials

BACKGROUND AND STUDY AIMS

Obesity is a recognised risk factor for poor bowel preparation in retrospective studies whilst corresponding data in prospective trials are marginally reported. Aims are to evaluate the relation between body mass index (BMI) and preparation quality in retrospective and interventional prospective settings and within a single centre.

PATIENTS AND METHODS

Data from a recent colorectal cancer screening registry were retrospectively analysed for the relation between BMI and adequacy of preparation. Patients were categorised as underweight (BMI<20kg/m(2)), normal (20-25kg/m(2)), overweight (25-30kg/m(2)), and obese (>30kg/m(2)). Data from a recent prospective colon preparation trial were similarly analysed.

RESULTS

541 registry patients were included. Multivariate analysis showed BMI to be an independent risk factor for inadequate preparation. Obesity was associated with odds ratio (OR) of 5.3 [95% confidence interval (CI) 1.4-19.8; p=0.01] compared to normal BMI. A significant difference was also noted in underweight but otherwise healthy individuals (OR=11.1, 95% CI 2-60; p=0.005). In the prospective study of 195 patients, obese patients had comparable rates of inadequate preparation to normal-weight individuals (OR=0.7, 95% CI 1.1-3.96; p=0.68). Underweight patients had a significantly worse preparation compared to normal BMI individuals (OR=8, 95% CI 1.1-58; p=0.04).

CONCLUSIONS

In real life, bowel preparations in obese individuals have a lower quality in comparison to normal individuals. This finding is not replicated in clinical trials. This discrepancy is likely the result of focused patient education suggesting that this is primarily a dietary compliance phenomenon. Underweight individuals appear to have worse quality of preparation independent of study design or setting.

Bowel cleansing before colonoscopy: Balancing efficacy, safety, cost and patient tolerance

Effective colorectal cancer screening relies on reliable colonoscopy findings which are themselves dependent on adequate bowel cleansing. Research has consistently demonstrated that inadequate bowel preparation adversely affects the adenoma detection rate and leads gastroenterologists to recommend earlier follow up than is consistent with published guidelines. Poor preparation affects as many as 30% of colonoscopies and contributes to an increased cost of colonoscopies. Patient tolerability is strongly affected by the preparation chosen and manner in which it is administered. Poor tolerability is, in turn, associated with lower quality bowel preparations. Recently, several new developments in both agents being used for bowel preparation and in the timing of administration have brought endoscopists closer to achieving the goal of effective, reliable, safe, and tolerable regimens. Historically, large volume preparations given in a single dose were administered to patients in order to achieve adequate bowel cleansing. These were poorly tolerated, and the unpleasant taste of and significant side effects produced by these large volume regimens contributed significantly to patients’ inability to reliably complete the preparation and to a reluctance to repeat the procedure. Smaller volumes, including preparations that are administered as tablets to be consumed with water, given as split doses have significantly improved both the patient experience and efficacy, and an appreciation of the importance of the preparation to colonoscopy interval have produced additional cleansing.

2-Litre polyethylene glycol-citrate-simethicone plus bisacodyl versus 4-litre polyethylene glycol as preparation for colonoscopy in chronic constipation

BACKGROUND

Chronic constipation is a risk factor of inadequate bowel preparation for colonoscopy; however, no large clinical trials have been performed in this subgroup of patients.

AIMS

To compare bowel cleansing efficacy, tolerability and acceptability of 2-L polyethylene-glycol-citrate-simethicone (PEG-CS) plus 2-day bisacodyl (reinforced regimen) vs. 4-L PEG in patients with chronic constipation undergoing colonoscopy.

METHODS

Randomized, observer-blind, parallel group study. Adult outpatients undergoing colonoscopy were randomly allocated to 2-L PEG-CS/bisacodyl or 4-L PEG, taken as split regimens before colonoscopy. Quality of bowel preparation was assessed by the Ottawa Bowel Cleansing Scale (OBCS). The amount of foam/bubble interfering with colonic visualization was also measured.

RESULTS

400 patients were enrolled. There was no significant difference in successful cleansing (OBCS score ≤6): 80.2% in the 2-L PEG-CS/bisacodyl vs. 81.4% in the 4-L PEG group. Significantly more patients taking 2L PEG-CS/bisacodyl showed no or minimal foam/bubbles in all colonic segments (80% vs. 63%; p<0.001). 2-L PEG-CS/bisacodyl was significantly more acceptable for ease of administration (p<0.001), willingness to repeat (p<0.001) and showed better compliance (p=0.002).

CONCLUSION

Split 2-L PEG-CS plus bisacodyl was not superior to split 4-L PEG for colonoscopy bowel cleansing in patients with chronic constipation; however, it performed better than the standard regimen in terms of colonic mucosa visualization, patient acceptance and compliance.

What Influences the Quality of Prevention Colonoscopy?

Background

Colorectal cancer still has a high incidence and mortality. Although colonoscopy is considered as gold standard of colorectal cancer screening, there still exists an unsatisfactory level of adenomas missed in screening and surveillance colonoscopy. Furthermore, patients bear the burden of potentially unpleasant and painful examination and preparation procedures.

Method

A search of the literature using PubMed was carried out, supplemented by a review of the programs of the Digestive Disease Week (DDW) and the United European Gastroenterology Week (UEGW) 2011-2013.

Results

Several new approaches to colonoscopy were described: water, CO₂ and cap colonoscopy, and application of spasmolytics such as hyoscine butylbromide and glucagon. The use of these methods does not necessitate the purchase of new endoscopes. They are feasible and safe, facilitate achieving the aim of more comfort and less pain, and perhaps allow lower doses of sedatives to be used. However, a clear effect on procedure time is lacking. Furthermore, the published data do not consistently answer the question of whether these techniques have a positive impact on the most important goal, the better detection of carcinoma precursors.

Conclusion

More efforts to optimize bowel preparation have to be made to improve visualization of the mucosal surface. The most reliable criteria for the quality of screening and surveillance colonoscopy remain a minimum cecal intubation rate of >90%, a withdrawal time of at least 6 or better 9 min, and an adenoma detection rate of >20%. These results should be achieved with a complication rate lower than 1%, including polypectomy.

Predicting inadequate bowel preparation for colonoscopy in participants receiving split-dose bowel preparation: development and validation of a prediction score

BACKGROUND

Adequate bowel preparation is important for optimal colonoscopy. It is important to identify patients at risk for inadequate bowel preparation because this allows taking precautions in this specific group.

OBJECTIVE

To develop a prediction score to identify patients at risk for inadequate bowel preparation who may benefit from an intensified bowel cleansing regimen.

DESIGN

Patient and colonoscopy data were prospectively collected, whereas clinical data were retrospectively collected for a total of 1996 colonoscopies in participants who received split-dose bowel preparation. Multivariate logistic regression analyses were conducted in a random two-thirds of the cohort to develop a prediction model. Validation and evaluation of the discriminative power of the prediction model were performed within the remaining one-third of the cohort.

SETTING

Four centers, including one academic and three medium-to-large size nonacademic centers.

PATIENTS

Consecutive colonoscopies in November and December 2012. Mean age was 57.3 ± 15.9 years, 45.8% were male and indications for colonoscopy were screening and/or surveillance (27%), abdominal symptoms and/or blood loss and/or anemia (60%), inflammatory bowel disease (9%), and others (4%).

INTERVENTIONS

Colonoscopy.

MAIN OUTCOME MEASUREMENTS

Inadequate bowel preparation defined as Boston Bowel Preparation Scale score <6.

RESULTS

A total of 1331 colonoscopies were included in the development cohort, of which 172 (12.9%) had an inadequate bowel preparation. Independent factors included in the prediction model were American Society of Anesthesiologists Physical Status Classification System score ≥3, use of tricyclic antidepressants, use of opioids, diabetes, chronic constipation, history of abdominal and/or pelvic surgery, history of inadequate bowel preparation, and current hospitalization. The discriminative ability of the scale was good, with an area under the curve of 0.77 in the validation cohort.

LIMITATIONS

Study design partially retrospective, no data on patient compliance.

CONCLUSION

We developed a validated, easy-to-use prediction scale that can be used to identify subjects with an increased risk of inadequate bowel preparation with good accuracy.

[Bowel preparation for colonoscopy. Any significant progress on the horizon?]

Colonoscopy is the method of choice for colorectal cancer screening. To be effective, screening colonoscopy must have high quality standards. The key element is the quality of the preparation. However, up to 20% of patients are inadequately prepared and, at present, anterograde washing is the least tolerated part of the procedure. In the choice of preparation, safety is a prerequisite and efficacy is a priority. Tolerance is a secondary but nevertheless influential factor in the quality of preparation and has consequently been the primary focus of many recent studies. In the last few years, a rapidly increasing number of studies have evaluated new drugs, dosages and adjuvant therapies to improve efficacy and tolerability. These studies have collaterally shown that inadequate preparation and lack of adherence to the prescribed regimen can be partially predicted, making it essential to identify this patient subgroup and invest the necessary effort in their instruction. New individualized and flexible approaches are expected for the different clinical scenarios. The search for the ideal colonoscopy preparation, which would be tolerable, safe and above all effective, remains open.

Miralax with gatorade for bowel preparation: a meta-analysis of randomized controlled trials

OBJECTIVES

Polyethylene glycol (PEG) is a very popular bowel preparation for colonoscopy. However, its large volume may reduce patient compliance, resulting in suboptimal preparation. Recently, a combination of Miralax and Gatorade has been studied in various randomized controlled trials (RCTs) as a lower volume and more palatable bowel preparation. However, results have varied. Therefore, we conducted a meta-analysis assessing the use of Miralax-Gatorade (M-G) vs. PEG for bowel preparation before colonoscopy.

METHODS

Multiple databases were searched (January 2014). RCTs on adults comparing M-G (238-255 g in 1.9 l that is 64 fl oz) vs. PEG (3.8-4 l) for bowel preparation before colonoscopy were included. The effects were analyzed by calculating pooled estimates of quality of bowel preparation (satisfactory, unsatisfactory, excellent), patient tolerance (nausea, cramping, bloating), and polyp detection by using odds ratio (OR) with fixed- and random-effects models.

RESULTS

Five studies met inclusion criteria (N=1,418), with mean age ranging from 53.8 to 61.3 years. M-G demonstrated statistically significantly fewer satisfactory bowel preparations as compared with PEG (OR 0.65; 95% confidence interval (CI): 0.43-0.98, P=0.04) but more willingness to repeat preparation (OR 7.32; 95% CI: 4.88-10.98, P<0.01). Furthermore, no statistically significant differences in polyp detection (P=0.65) or side effects were apparent between the two preparations for nausea (P=0.71), cramping (P=0.84), or bloating (P=0.50). Subgroup analysis revealed similar results for split-dose M-G vs. split-dose PEG.

CONCLUSIONS

M-G for bowel preparation before colonoscopy was inferior to PEG in bowel preparation quality while demonstrating no significant improvements in adverse effects or polyp detection. Therefore, PEG appears superior to M-G for bowel preparation before colonoscopy.

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

BACKGROUND AND AIM

Prior studies have reported 2-L polyethylene glycol (PEG) plus ascorbic acid (PEG + Asc) is an effective alternative to standard 4-L PEG for bowel preparation before colonoscopy, but they are limited because of some confounders. Therefore, we compared the efficacy, patient compliance, satisfaction, and safety of 2-L PEG + Asc versus 4-L PEG for bowel cleansing in optimal preparation strategies.

METHODS

In this prospective, randomized, single-blind trial, consenting outpatients were randomly assigned to one of two arms. All colonoscopies were scheduled in the morning and cleansing solutions were administered as a split-dose regimen. Bowel-cleansing efficacy in three different segments was measured on a five-point scale with four-point overall grading. Patients' opinions of the preparation regimens were obtained by questionnaire.

RESULTS

There was no significant difference between the 2-L PEG + Asc (159/163; 97.5%) and 4-L PEG (162/164; 98.8%) with respect to the overall success of bowel cleansing (mean difference = -1.3 [-4.1-∞]). Patient compliance, acceptability, and satisfaction were better in the 2-L PEG + Asc arm than the 4-L PEG arm (P < 0.05). Additionally, the incidence of side effects was lower in the 2-L PEG + Asc than the 4-L PEG (overall, 57.7% vs 73.2%, P < 0.05). However, no significant difference was seen in patients' rating of taste.

CONCLUSIONS

In an optimal preparation setting, 2-L PEG + Asc has equal efficacy as a bowel cleanser prior to colonoscopy as 4-L PEG, with the advantages of better patient compliance, satisfaction, and safety.