OBJECTIVETo verify the efficacy of Jianpi Tiaogan Wenshen Recipe (JTWR) in treating diarrhea-predominant irritable bowel syndrome (IBS-D) and to analyze its therapeutic mechanism through observing the effect of JTWR on clinical symptoms and rectal sensibility in patients.

METHODSWith a prospective, randomized controlled trial adopted, 80 patients with IBS-D were assigned randomly equally and to two groups. The treatment group was treated with JTWR, and the control group was treated with pinaverium bromide tablet (PVB), all for four weeks. Patients' symptoms, such as abdominal discomfort, pain, and distension; frequency of defecation; appearance of stool; and occurrence of tenesmus were recorded before and after treatment by scoring, and the rectal sensitivity was detected as well. Patients with therapeutic effect of cured and markly effective were followed up four weeks after withdrawal of medication.

RESULTSThree cases in the treatment group and four cases in the control group were dropped. Except the appearing of mucus stool, no statistically significant difference was shown between the two group in all other symptoms, either at before or after treatment; but the end point scores of individual symptoms between pre- and post-treatment were different statistically in both groups (P<0.05). Per-protocol population set (PPS) analysis on comprehensive effect showed that the total effective rate and the cure rate in the treatment group was 81.1% (30/37) and 24.3% (9/37), and those in the control group, 80.6% (29/36) and 19.4% (7/36) respectively; while the full analysis set (FAS) showed a result of 80.0% (32/40) and 22.5% (9/40) vs 77.5% (31/40) and 17.5% (7/40) respectively, all with insignificant difference between groups (P>0.05). Follow-up study showed that relapse or aggravation of disease occurred in four cases in the treatment group and 12 in the control group respectively, showing significant difference between groups (P<0.01). Rectal sensitivity examination showed that the rectal thresholds of sensation, defecation, and maximum tolerable volume were improved in both groups after treatment (P<0.05), but showed no significant difference between groups (P>0.05).

CONCLUSIONSJTWR is effective in treating IBS-D, with the effect better than PVB in improving mucus stool, also in the remote effect. Its therapeutic mechanism is possibly by way of adjusting the sensitivity of rectum.