Randomized trial comparing oral sulfate solution with 4-L polyethylene glycol administered in a split dose as preparation for colonoscopy

Background and Aim: The present study aimed to evaluate the non-inferiority of low-volume oral sulfate solution (OSS) to 4-L polyethylene glycol (PEG) solutions administered in a split-dose regimen as bowel preparation for colonoscopy. The safety and tolerability were also compared between the two regimens. Methods: In this prospective, randomized, single-blind, active-control, parallel group, and non-inferiority trial, consecutive outpatients and health checkup recipients aged 19–65 years undergoing elective colonoscopy were enrolled to receive OSS or 4-L PEG in a split-dose regimen. The quality of bowel preparation was evaluated using the Boston Bowel Preparation Scale. The occurrence of any adverse events, acceptance, compliance, and satisfaction during bowel preparation were evaluated by participant interviews. Results: Overall, 210 participants were randomized, and 199 were administered by the study agents. Adequate bowel preparation was achieved in 98.0% (97/99) of the OSS group, which was non-inferior to the PEG group (96%; 96/100) with a difference of +2.8% (95% confidence interval; −2.8, +6.8). There were no differences in the incidence of adverse events except for abdominal pain, which was more frequent in the OSS (7.1%, 7/99) than in the PEG (1.0%, 1/100; P = 0.035) group. Acceptance, compliance, and satisfaction were significantly higher in the OSS than in the PEG group (all P < 0.05). Conclusions: Split-dose OSS was non-inferior to split-dose 4-L PEG with regard to bowel preparation efficacy before colonoscopy in adult outpatients or screening colonoscopy recipients aged ≤65 years with acceptable safety and superior tolerability.