IBS, Diarrhea Predominant

This trial is a randomized, double-blind, placebo-controlled, parallel-group, multicenter Phase III clinical trial. Its purpose is to evaluate the efficacy and safety of Changji'an Capsules in subjects with diarrhea-predominant irritable bowel syndrome (liver-qi invading spleen syndrome) after 8 weeks of treatment.

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder characterized by recurrent abdominal pain and altered bowel habits. Under the Rome IV criteria, IBS can be classified into constipation-predominant (IBS-C), diarrhea-predominant (IBS-D), mixed (IBS-M), and unclassified (IBS-U) subtypes. IBS-D represents one of the most clinically disruptive phenotypes due to the combined burden of abdominal pain and frequent loose stools1. These symptoms are the major drivers of impaired quality of life and healthcare utilization. Despite available pharmacologic treatments, recurrence rates remain high and adverse effects often limit patient satisfaction, creating an unmet need for safe and effective alternative therapies. Transcutaneous Electrical Acustimulation (TEA) is an emerging therapy which delivers appropriate electrical stimulation to acupoints that are in the vicinity of peripheral nerves through surface electrodes, has been demonstrated to improve bowel symptoms and visceral hypersensitivity by modulating autonomic function and brain-gut interaction2. Previous trials of TEA in IBS have shown improvement in bowel symptoms, pain, and quality of life, with good safety and tolerability2,3. However, multicenter evidence for IBS-D is lacking. This trial aims to evaluate whether TEA can improve overall symptoms in patients with IBS-D. Specifically, the primary objective is to assess the effect of TEA on the composite responder rate, defined by concurrent improvement in both abdominal pain and loose stool days. Secondary objectives include evaluating broader symptom severity, stool characteristics, as well as on quality of life, psychological symptoms, and the durability of clinical benefits during follow-up.