A Randomized Trial Comparing the Bowel Cleansing Efficacy of Sodium Picosulfate/Magnesium Citrate and Polyethylene Glycol/Bisacodyl (The Bowklean Study)

Bowel cleansing is essential for a successful colonoscopy, but the ideal clearing agent and the volume have yet to be determined. A small-volume cleanser is important for patient compliance. This study aimed to compare the bowel cleansing efficacy, safety, tolerability, and acceptability of a 300-mL small-volume sodium picosulfate/magnesium citrate (PSMC) preparation-Bowklean with one 2-L polyethylene glycol (PEG)/bisacodyl-Klean-Prep/Dulcolax preparation under identical dietary recommendations. This multicenter, randomized, parallel-group, pre-specified noninferiority study enrolled 631 outpatients scheduled to undergo colonoscopy (Bowklean = 316 and Klean-Prep/Dulcolax = 315). After bowel preparation, an independent evaluator blinded to the subject's treatment allocation rated the quality of the colon cleansing. Efficacy was evaluated using the Aronchick Scale and Ottawa Bowel Preparation Scale (OPBS). Safety was assessed by monitoring adverse events. Tolerability and acceptability were measured via a patient questionnaire. Bowklean was non-interior to Klean-Prep/Dulcolax in overall colon cleansing but was associated with significantly better preparation quality. Notably, Bowklean was associated with significantly greater tolerability and acceptability of bowel preparations than Klean-Prep/Dulcolax. Safety profiles did not differ significantly between the groups. Our data indicate that Bowklean is a more effective and better-tolerated bowel cleansing preparation before colonoscopy than Klean-Prep/Dulcolax. Bowklean may therefore increase positive attitudes toward colonoscopies and participation rates.