AT A GLANCE

A new study published in BMC Gastroenterology suggests that optimal dose for simethicone (SIM) for afternoon colonoscopy.¹

“SIM can enhance bowel preparation efficiency, but the optimal dose for patients undergoing afternoon colonoscopy is still unclear,” explain study authors Cai et al. “This study compares bowel preparation efficiency and [the] adenoma detection rate (ADR) between patients receiving 3 L of polyethylene glycol electrolyte solution (PEG-ELS) with 200 mg [of] SIM or 1200 mg [of] SIM for afternoon colonoscopy.”

As part of a prospective, randomized, and observer-blinded trial, the authors enrolled consecutive patients undergoing colonoscopy and compared the effects of two SIM dosages (200 mg and 1200 mg) added to a 3 L PEG-ELS regimen. The primary outcome of interest was the rate of adequate bowel preparation, while secondary outcomes included the Bubble Scale (BS) score and ADR.

According to the authors, 668 participants were randomly assigned to either the 200-mg group (n = 332) or the 1200-mg SIM group (n = 336). Ultimately, no significant differences were observed in the adequate bowel preparation rate (95.8% vs. 97.6%) or the ADR (22.3% vs. 25.6%). Both regimens were well tolerated and accepted by participants, as assessed through a standardized patient questionnaire.

The authors conclude that “200 mg versus 1200 mg of SIM in 3 L [of] PEG-ELS for afternoon colonoscopy demonstrated no statistically significant difference in bowel cleansing quality, ADR, and bowel preparation–related adverse events.”

“This evidence supports the clinical feasibility of 200 mg [of] simethicone as an effective alternative for optimizing colonic preparation while maintaining procedural standards,” they note.

Reference

1.     Cai X, Xue P, Li Y, et al. Comparative efficacy of 200 mg versus 1200 mg of simethicone with 3 L polyethylene glycol electrolyte solution for afternoon colonoscopy: a randomized controlled trial. BMC Gastroenterol. 2025;25(1):722.