Efficacy and Safety of Bowel Cleansing with Mini S-Oral Sulfate Tablet versus the Conventional Oral Sulfate Tablet: A Prospective, Randomized, Investigator-Blinded, Multicenter, Noninferior, Phase 3 Trial

Abstract

Background/Aims: Conventional oral sulfate tablets (OSTs) and mini-OSTs have gained popularity for bowel preparation in South Korea. This study aimed to evaluate the efficacy, tolerability, and safety of mini S-OSTs, which have fewer tablets and include simethicone compared to the mini-OSTs. Methods: This was a prospective, randomized, investigator-blinded, multicenter, and noninferior phase 3 trial conducted between August 2023 and January 2024. The efficacy, safety, and tolerability were compared among a mini S-OST split dose group, mini S-OST non-split dose group and conventional OST group. To evaluate the occurrence of gastric mucosal lesions, gastroscopy was also performed. Results: High-quality preparation was achieved in the mini S-OST split dose group and conventional OST group according to both the full analysis set and per-protocol set analyses, without significant differences. Tolerability metrics were more favorable in the mini-OST group. The hematin content tended to decrease and the number of erosions was reduced in the mini S-OST split dose group compared with the conventional OST group according to the gastroscopy results. Adverse events were comparable between the conventional OST and mini S-OST split dose groups. The mini S-OST non-split dose group showed no difference in overall successful cleaning, but the proportion of high-quality cleaning in the ascending colon was lower than that in the mini S-OST split dose group and conventional OST group. Conclusions: Compared with conventional OST, the mini S-OST split dose showed excellent efficacy, comparable safety and tolerability, with less gastric injury (ClinicalTrial.gov identifier NCT06287606). (Gut Liver, Published online November 27, 2025)