Randomized Controlled Trial
Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Endosc. Jun 16, 2019; 11(6): 413-423
Published online Jun 16, 2019. doi: 10.4253/wjge.v11.i6.413
Randomized, double-blinded, placebo-controlled trial evaluating simethicone pretreatment with bowel preparation during colonoscopy
Mohit Rishi, Jaskarin Kaur, Mark Ulanja, Nicholas Manasewitsch, Molly Svendsen, Abubaker Abdalla, Shashank Vemala, Julie Kewanyama, Karmjit Singh, Nirmal Singh, Nageshwara Gullapalli, Eric Osgard
Mohit Rishi, Jaskarin Kaur, Mark Ulanja, Nicholas Manasewitsch, Molly Svendsen, Abubaker Abdalla, Shashank Vemala, Nageshwara Gullapalli, Department of Internal Medicine, University of Nevada, Reno School of Medicine, Renown Regional Medical Center, Reno, NV 89502, United States
Julie Kewanyama, Eric Osgard, Gastroenterology Consultants, LTD, Reno, NV 89502, United States
Karmjit Singh, Aureus Univeristy School of Medicine, Oranjestad 31C, Aruba
Nirmal Singh, American International Medical University, Gross Islet 7610, Saint Lucia
Author contributions: Rishi M, Kaur J, Osgard E designed the research; Rishi M, Kaur J, Osgard E, Manasewitsch N, Svendsen M, Kewanyama J, Vemala S, Abdalla A, Singh K, Singh N performed the study, collected data, and helped prepare the manuscript; Ulanja M performed analysis of data; Rishi M, Kaur J, and Ulanja M wrote the final manuscript; Gullapalli N, Osgard E reviewed the manuscript.
Institutional review board statement: This study was approved by the University of Nevada Human Research and Institutional Review Board on December 21, 2017.
Clinical trial registration statement: The study was registered at ClinicalTrials.gov identifier NCT03410524.
Informed consent statement: All subjects gave informed consent prior to study inclusion.
Conflict-of-interest statement: None of the participating authors have any conflicts of interest to declare.
Data sharing statement: Dataset and statistical evaluation is available upon request from the corresponding author at mohitrishi1226@gmail.com
CONSORT 2010 statement: The authors have read the CONSORT 2010 statement, and the manuscript was prepared and revised according to the CONSORT 2010 statement.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Mohit Rishi, MD, Academic Research, Department of Internal Medicine, University of Nevada, Reno School of Medicine, Renown Regional Medical Center, 1155 Mill St. W11, Reno, NV 89502, United States. mrishi@unr.edu
Telephone: +1-775-3275174 Fax: +1-775-98239000
Received: April 6, 2019
Peer-review started: April 8, 2019
First decision: May 16, 2019
Revised: June 1, 2019
Accepted: June 10, 2019
Article in press: June 10, 2019
Published online: June 16, 2019
Processing time: 71 Days and 6.4 Hours
ARTICLE HIGHLIGHTS
Research background

The presence of small air bubbles and foam are an impediment to a successful colonoscopy. They impair an endoscopist’s view and diminish the diagnostic accuracy of the study. This has been particularly noted to be of concern with the switch to lower volume polyethylene glycol (PEG) and bisacodyl combination preparation.

Research motivation

Simethicone is commonly added to water for irrigation during colonoscopy to clear bubbles/ foam and to improve mucosal visibility. However, recent endoscope manufacturer guidelines recommend against intraprocedural irrigation with simethicone infused water due to concerns for its retention in irrigation channels despite reprocessing. Our initial motivation to perform this study was to evaluate whether the addition of liquid simethicone to low volume PEG bowel preparation would improve intraluminal visibility during colonoscopy and thereby eliminate the need for intra procedural irrigation of simethicone.

Research objectives

The primary outcome measurement was the comparison of bubbles and foam utilizing the Intraluminal Bubbles Scale. Secondary outcomes measured include Boston Bowel Preparation Scale measurement, total number of polyps, polyp size differentiation, polyp laterality, total adenoma detection, cecal insertion time, withdrawal time, and adverse events.

Research methods

This is a prospective, parallel-group, randomized, double-blinded and placebo-controlled study conducted at two gastroenterology community-based outpatient endoscopy centers. Adult participants were instructed to add liquid simethicone to 2-liter split bowel preparation with bisacodyl. Patients, endoscopists, and enrolling staff were blinded during patient enrollment. Endoscopists were also blinded during conduction of the procedure. Intraluminal Bubbles Scale was recorded during the procedure and a grade of 1-4 was allocated correlating with the percent circumference of colonic mucosa clear of all bubbles/foam. Grade 1 was equivocal to > 90% mucosa clear of bubbles not requiring irrigation; Grade 2 was 75%-89% mucosa clear of bubbles not requiring irrigation; Grade 3 was 50%-74% mucosa clear of bubbles and required irrigation; Grade 4 was < 50% mucosa clear of bubbles and required irrigation.

Research results

Higher Intraluminal Bubbles grades III and IV (less than 75% of the mucosa cleared of bubbles/foam requiring intervention with simethicone infused wash) were detected in the placebo group [Simethicone n = 4/84 vs Placebo n = 20/84 (P = 0.007)]. BBPS total score was 7.42 (SD = ± 1.51) in the simethicone group and 7.28 (SD = ± 1.44) in the placebo group (P = 0.542) from a total of 9. Significantly higher number of adenomas were detected in the simethicone group (P = 0.001).

Research conclusions

The addition of simethicone to bowel preparation is well advised for its anti-foaming properties during colonoscopy. The results of this study suggest that addition of oral simethicone can improve bowel wall visibility and reduce the need for intraprocedural irrigation.

Research perspectives

Larger research studies with screening colonoscopy patients should be carried out to evaluate the effect of simethicone on adenoma detection rate.