Safety and Efficacy of Lyophilized Faecal Microbiota Transplantation Via Capsules in Treatment of Irritable Bowel Syndrome

The goal of this clinical trial is to learn if oral capsules containing lyophilized fecal microbiota transplantation (FMT) can safely and effectively treat refractory irritable bowel syndrome (IBS) in adults aged 18-65 years. The main questions it aims to answer are: Does treatment with lyophilized FMT capsules reduce IBS symptom severity compared with placebo? Does treatment with lyophilized FMT capsules improve quality of life, anxiety, and depression in patients with IBS? Are there differences in the frequency of adverse events between participants receiving FMT capsules and those receiving placebo? Researchers will compare lyophilized FMT capsules to placebo capsules to see if FMT reduces IBS symptoms and improves quality of life and mental health. Participants will: Be randomly assigned to receive either lyophilized FMT capsules or placebo capsules for three consecutive days. Take the capsules under supervision after receiving a proton pump inhibitor before the first dose. Complete questionnaires assessing symptom severity, quality of life, anxiety, and depression at baseline, 4 weeks, and 12 weeks after treatment. Attend follow-up visits at 4 weeks and 12 weeks after treatment and receive a telephone follow-up call 10 days after capsule ingestion. Report any adverse events and have vital signs and medical information monitored during follow-up. This study will help determine whether oral lyophilized FMT capsules are a safe and effective treatment option for adults with refractory IBS.