Efficacy of a single low dose of esketamine for patients with irritable bowel syndrome: study protocol for a randomised controlled trial.
BMJ open June 23, 2025 Zhe Sun, Lei Jiang, Yan Xing et al.
Irritable bowel syndrome (IBS) is a common disorder of gut-brain interaction involving recurrent abdominal pain and altered bowel habits. Conventional treatments are often unsatisfactory. This trial hypothesizes that a single low dose of esketamine, which has rapid antidepressant effects, may alleviate IBS symptoms. The study is a single-centre, randomized, double-blind, placebo-controlled trial enrolling 92 patients per group across three severity levels. The primary outcome is the IBS Severity Scoring System measured at baseline and up to six weeks after colonoscopy. Secondary outcomes include quality of life, stool form, anxiety, depression, and somatic symptoms. The protocol is approved and registered.