Systematic review and meta-analysis of randomized controlled trials of Simethicone for gastrointestinal endoscopic visibility

Background. The value of supplemental use of Simethicone in endoscopy including capsule endoscopy (CE), colonoscopy and esophagogastroduodenoscopy is not addressed and is controversial. Methods. A systematic review and meta-analysis of randomized controlled studies on the use of Simethicone for endoscopy were carried out. The effects of this preparation on the following endpoints were examined: small bowel visualization quality (SBVQ), completion rate, gastric transit time, small bowel transit time, diagnostic yield, efficacy of bowel preparation, degree of air bubbles and duration time. Results. A total of 13 studies were eligible in this meta-analysis; 4 studies comparing purgative or fasting plus Simethicone with purgative or fasting alone for capsule endoscopy were identified. For patients who had supplemental Simethicone before CE, the SBVQ was significantly better ([odds ratio] OR = 2.84, 95% CI: 1.74-4.65, p = 0.00), and the completion rate was comparable (OR = 0.80, 95% CI: 0.44-1.44, p = 0.454). Also, 7 studies comparing purgative plus Simethicone with purgative alone for colonoscopy were identified. For patients who had supplemental Simethicone before colonoscopy, the efficacy of colon preparation was comparable (OR = 2.06, 95% CI: 0.56-7.53, p = 0.27), but the air bubbles were significantly decreased (OR = 39.32, 95% CI: 11.38-135.86, p = 0.00). Conclusion. Supplemental use of Simethicone before endoscopy improves the SBVQ, especially for patients who received no purgative, but does not affect the CE completion rate. It decreases air bubbles in the colonic lumen, but does not improve bowel preparation. And its effect on diagnostic yield remains controversial.