The Effect on Colon Visualization During Colonoscopy of the Addition of Simethicone to Polyethylene Glycol-Electrolyte Solution: A Randomized Single-Blind Study

Abstract

OBJECTIVES:Colonic bubbles associated with polyethylene glycol-electrolyte solution (PEG-ELS) are common and obscure mucosal visualization. This study aimed to determine whether adding simethicone decreases the incidence of bubbles.METHODS:Prospective, single-blind, randomized comparison of split dose PEG-ELS vs. PEG-ELS+simethicone (PEG-S) for outpatient colonoscopy. Bubble severity for colonic segments was assessed on withdrawal as A=no/minimal bubbles, B=moderate bubbles/interfere with detecting 5 mm polyp, C=severe bubbles/interfere with detecting 10 mm polyp. Primary end point was Grade B or C bubbles in any colon segment. Secondary end points were cleansing quality, incidence and severity of side effects, and polyp detection.RESULTS:One hundred and thirty nine patients enrolled; 13 withdrew before colonoscopy. Of 123 patients evaluated, 62 took PEG-S and 61 PEG-ELS. The incidence of grade B or C bubbles was much lower with PEG-S compared with PEG-ELS (2% vs. 38% P=0.001). Overall cleansing (excellent or good) quality was not significantly different for either the whole colon (89% PEG-ELS, 94% of PEG-S, P=0.529) or right colon (88% PEG-ELS, 94% PEG-S, P=0.365). More PEG-S patients had excellent rather than good preps (whole colon 53% vs. 28%, P=0.004; right colon 53% vs. 35%, P=0.044). Need for any flushing was less with PEG-S (38% vs. 70%, P=0.001). The groups were not significantly different with respect to total procedure and withdrawal times, incidence or severity of side effects, or number of polyps/patient or adenomas/patient.CONCLUSIONS:Adding simethicone to PEG-ELS effectively eliminates bubbles, substantially reduces the need for flushing, and results in more excellent preparations.

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

“…To detect an ADR increased to 27.9% with 80% power using a cut‐off for statistical significance of 0.05 would require a sample size of at least 1412 patients, and obviously, there was no single trial that met this criterion. Additionally, according to the forest plot, it is obvious that, excepting the two RCTs conducted by Matro et al . and de Leone et al ., the other four trials reported numerically higher ADRs during colonoscopy in the SIM group.…”

“…In order to improve the level of bowel cleansing, simethicone (SIM), a kind of oral antifoaming agent, has been added to several PEG‐based bowel preparation regimens, for it reduces bubbles in bowel segments so as to improve visualization of the colonic mucosa and promote emission of excessive gas …”

“…Although several randomized controlled trials (RCTs) have reported that supplemental SIM can improve bowel preparation, there is no consensus as to whether it can ultimately increase the ADR during colonoscopy, which is more clinically concerned to the prevention of CRC. Two RCTs have reported the significantly high ADR in SIM group, but other several RCTs have revealed inconsistent conclusions . Thus, to date, it is still unclear whether supplemental SIM for bowel preparation could increase ADR during colonoscopy.…”

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

“…Our search strategy identified 535 potentially relevant records after excluding duplicates. After careful review, 36 studies that met inclusion criteria were further evaluated for eligibility, and 12 full‐text articles from 2009 to 2017 were included in this meta‐analysis . The review process is illustrated by a flowchart of Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (Fig.…”

“…Simethicone, an anti‐foaming agent, has long been used to eliminate bubbles by being added to the irrigation water or being an adjunct of bowel preparation regimens . One meta‐analysis showed that oral simethicone helps reduce bubbles and improves visibility in upper gastrointestinal endoscopy, but the ADR was not evaluated because few studies had addressed this issue at the time it was published.…”