AIM To study combined therapy effect of Glutamine Acid Amide Campound capsules(GAAC)and Bifid Tiple Viable(BTV) preparation on irritable bowel syndrome characterized by Diarrhea compared with SMECA Sachet.METHOD GAAC & BTV group was dosed of both 9 GAAC capsules and 420mg BTV preparation per day in 3 divided dosage.Control group was administrated 9g sachets per day in 3 divided dosages.Diarrhoea symptoms of two groups were observed after 14 days′ administration.RESULTS The significant effect on diarrhoea of GAAC&BTV group is 75.6%,and 51.2% higher than control group(P<0.01).Total effect rate of GAAC&BTV groups was also higher than control group.CONCLUSION GAAC and BTV are potential drugs in therapy of diarrhoea IBS.