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

Abstract 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.