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.
Meet the Western medicine diagnostic criteria for diarrhea-predominant irritable bowel syndrome;
Meet the Traditional Chinese Medicine syndrome differentiation criteria for liver Qi invading the spleen;
Aged ≥18 and ≤65 years, regardless of gender;
Record daily the most severe abdominal pain, bloating, and abdominal discomfort NRS scores for the last week of the run-in period. At least one of these three items must meet the weekly average NRS score criterion (the weekly average of abdominal pain NRS is calculated as: total weekly score of abdominal pain NRS on days with Bristol Stool Form Scale type 6 or 7 stools / actual number of days with Bristol type 6 or 7 stools in that week; the average values for the other two items are calculated similarly) ≥3 points (11-point Numerical Rating Scale, NRS-11); meanwhile, for stool form, during the last week of the run-in period, there must be at least 2 days in which each day has at least one bowel movement of Bristol type 6 or 7;
Individuals with fewer than 3 spontaneous bowel movements per week during the induction period;
Individuals with stool consistency of type 1 or 2 (Bristol Stool Form Scale) on at least 2 days per week during the induction period;
Individuals confirmed to have infectious diarrhea, inflammatory bowel disease, parasitic infection, positive fecal occult blood tests and considered to have gastrointestinal bleeding (excluding hemorrhoids), colorectal tumors, malabsorption syndrome, lactose intolerance (based on medical history), and diarrhea caused by systemic diseases;
Individuals who have used other medications for irritable bowel syndrome within 1 week prior to screening;