Efficacy of 200 mg vs 1200 mg Simethicone with 3 L PEG for Afternoon Colonoscopy.

This study compared the effectiveness of 200 mg versus 1200 mg simethicone (SIM) added to 3 L polyethylene glycol electrolyte solution (PEG-ELS) for afternoon colonoscopy preparation. Conducted at Shenzhen People’s Hospital between February and July 2024, the randomized, endoscopist-blinded trial included 668 participants. Both groups consumed their bowel preparation between 9:00–11:00 AM for colonoscopies performed 4–6 hours later.

The primary outcome was bowel preparation adequacy, measured by the Boston Bowel Preparation Scale (BBPS). Both doses achieved comparable results: 95.8% adequate preparation for 200 mg versus 97.6% for 1200 mg. Secondary outcomes, such as mucosal visibility (Bubble Scale score), adenoma detection rate (ADR), and polyp detection, were statistically similar. Subgroup analysis showed slightly higher right-colon adenoma detection with 1200 mg SIM, but this did not affect overall ADR.

Adverse effects like nausea and bloating were slightly lower in the 200 mg group, and both doses had high patient acceptability. The 200 mg dose, costing $1 compared to $6 for 1200 mg, offers significant cost savings without compromising efficacy. The study concludes that 200 mg SIM is a safe, effective, and economical choice for afternoon colonoscopy preparation, pending validation in broader populations.