Optimal Timing of Simethicone Supplement for Bowel Preparation: A Prospective Randomized Controlled Trial

Abstract

Background and Aims. Simethicone (SIM), as an antifoaming agent, has been shown to improve bowel preparation during colonoscopy. However, the optimal timing of SIM addition remained undetermined. We aimed to investigate the optimal timing of SIM addition to polyethylene glycol (PEG) to improve bowel preparation. Methods. Eligible patients were randomly assigned to two groups: the SIM evening group (SIM addition to PEG in the evening of the day prior to colonoscopy) and the SIM morning group (SIM addition to PEG in the morning of colonoscopy). The primary outcome was Bubble Scale (BS). The secondary outcomes were Boston Bowel Preparation Scale (BBPS) and adenoma detection rate (ADR). Results. A total of 419 patients were enrolled in this study. The baseline characteristics of the patients were similar in both groups. No significant differences were observed in terms of BS (8.76 ± 0.90 vs. 8.65 ± 1.16, P = 0.81), ADR (34.1% vs. 30.8%, P = 0.47), Boston Bowel Preparation Scale (BBPS) (8.59 ± 0.94 vs. 8.45 ± 1.00, P = 0.15), and withdrawal time (8.22 ± 2.04 vs. 8.01 ± 2.51, P = 0.094) between the two groups. Moreover, safety and compliance were similar in both groups. However, the SIM evening group was associated with shorter cecal intubation time (3.80 ± 1.81 vs. 4.42 ± 2.03, P < 0.001), higher BS (2.95 ± 0.26 vs. 2.88 ± 0.38, P = 0.04) in the right colon, and diminutive ADR (62.5% vs. 38.6%, P = 0.022) in the right colon, when compared to the SIM evening group. Conclusions. The SIM addition to PEG in the evening of the day prior to colonoscopy can shorten cecal intubation time and improve BS scores and diminutive ADR of the right colon compared with the SIM addition to PEG in the morning of colonoscopy in bowel preparation.

When should patients take simethicone orally before colonoscopy for avoiding bubbles: A single-blind, randomized controlled study

“…A study showed that taking simethicone significantly reduced bubbles, [ 4 ] while a study was conducted to determine the most effective dose of simethicone [ 14 ] and another study was conducted to determine the most effective timing of taking simethicone. [ 9 , 10 ] Also, there was a study that posed mixing simethicone with 2 L of PEG-ascorbic acid solution for both bowel cleansing and eliminating bubbles was better. [ 5 ] There is no clearly established protocol to date, but when the results of previous studies are combined, it can be thought that taking 200 mg of simethicone on the day before the examination is most effective.…”

“…A study showed that taking simethicone significantly reduced bubbles, [4] while a study was conducted to determine the most effective dose of simethicone [14] and another study was conducted to determine the most effective timing of taking simethicone. [9,10] Also, there was a study that posed mixing simethicone with 2 L .796 †BB = the day before the examination and before bowel cleansing. ‡BA = the day before the examination and after bowel cleansing.…”

“…[ 6 , 9 ] There was a difference of 2% to 40% in BS between the groups on the day before the colonoscopy and on the day of the colonoscopy. [ 9 , 10 ] Based on these study results, the difference in BS between groups was estimated to be 25%. The number of patients required was at least 40 for each group with a power of 0.8, and an alpha value of 0.05.…”

“…Two studies on the optimal time for simethicone administration during bowel cleansing with split-dose PEG reported that taking simethicone the day before the test is the best approach to reduce bubbles in the colon. [ 9 , 10 ] However, these previous studies had limitations in that the administration time of simethicone was approximately divided as on the day before and on the day of colonoscopy. It is still questionable how to apply the results of these studies to actual clinical situations because patients still do not know when to take it exactly.…”

The Effect of Oral Simethicone in a Bowel Preparation in a Colorectal Cancer Screening Colonoscopy Setting: A Randomized Controlled Trial

“…However, it resulted in lower bubble scale scores and a lower intraprocedural use of simethicone [4]. Furthermore, the optimal timing of oral simethicone addition remains undetermined [9,10]. In summary, previous studies were mostly from Eastern countries, used low-volume PEG-based regimens or non-PEG-based agents, used simethicone in suspension, have shown conflicting results and only one study assessed colonoscopy results in a CRC screening setting.…”