Acupuncture for irritable bowel syndrome comorbid with anxiety and depression: study protocol for a placebo run-in, randomized clinical trial

Background: Gastrointestinal and psychological symptoms jointly motivate patients with irritable bowel syndrome (IBS) to seek medical care, with the latter often exacerbating the difficulty of achieving overall improvement. Although acupuncture has been shown to improve gastrointestinal symptoms in the general IBS population, the evidence in individuals with psychological disturbances remains insufficient. Methods: This will be a placebo run-in, randomized controlled trial. After the 1-week sham acupuncture intervention run-in period, the 80 eligible IBS patients without strong placebo responses will be randomly assigned to the true acupuncture (TA) group and sham acupuncture (SA) group. During the 4-week intervention period, all patients will receive the assigned intervention three times per week, followed by an 8-week follow-up. The primary endpoint is the response rate, defined as the proportion of patients with a decrease of greater than or equal to 50 points in the IBS Symptom Severity Scale (IBS-SSS) score from baseline at week 4. Secondary outcomes include the response rates at other time points, original IBS-SSS scores, Hospital Anxiety and Depression Scale (HADS), Visual Analog Scale (VAS) for abdominal pain, satisfaction with bowel habits, blinding assessment, and Credibility/Expectancy Questionnaire. Safety will be monitored and recorded during the trial. Discussion: This trial will provide individualized evidence for addressing IBS with key comorbidities while excluding placebo response. The results of this trial will be published in a peer-reviewed journal. Clinical Trial Registration: https://itmctr.ccebtcm.org.cn/mgt/project/view/1985616257155727360, identifier ITMCTR2025002100.