Objective To compare the difference in the therapeutic effects on diarrhea- type irritable bowel syndrome (D-IBS) between acupuncture based on soothing the liver and strengthening the spleen and western medicine. Methods Seventy cases were randomized into an acupuncture group and a western medicine group, 35 cases in each one. In the acupuncture group, the conventional acupuncture was applied at Tianshu {天枢 ST 25), Zusanli (足三里 ST 36), Shangjuxu {上巨虚 ST 37), Sanyinjiao (三阴交 SP 6), Taichong (太冲 LR 3) and so on. Electric stimulation was supplemented at bilateral ST 25. The treatment was given once a day, 3-4 treatments in a week. In the western medicine group, pinaverium bromide (dicetel) was prescribed for oral administration, 50 mg each time, three times a day. Four weeks made one session in the two groups. Separately, before treatment and after 1 session treatment, the integral of clinical symptom and the score in the scale of the quality of life measure for irritable bowel syndrome (IBS-Q OL) were observed for the patients in the two groups. The efficacy and recurrence rate were assessed in the two groups. Results The symptom integral and IBS-QOL score in the two groups were improved significantly after treatment Call P〈0.01), and the improvements in the acupuncture group were superior to that in the western medicine group (P〈0.01). The effective rate was 94.3% {33/35) in the acupuncture group, which was superior to 77.1% (27/35) in the western medicine group (P〈0.01). In 3 months, the recurrence rate was 36.4% (12/33) in the acupuncture group, which was lower apparently than 72.0% (18/25) in the western medicine group (P〈O.01). Conclusion Acupuncture therapy based on soothing the liver and strengthening the spleen achieves the superior efficacy on D-IBS as compared with western medication, pinaverium bromide. This therapy improves apparently the quality of life of the patients and is lower in recurrence rate.