OBJECTIVETo evaluate the effect of Shugan Jianpi Granule (, SJG) on the number of gut mucosal serotonin-positive cells (5-HT+C) in patients with irritable bowel syndrome (IBS) of stagnated Gan-qi attacking Pi (SGAP) syndrome type.METHODSTwenty-four patients were randomized equally into three groups. All were treated with the basic conventional treatment by cognition-behavior therapy with assistance of lactein 3 tablets thrice a day. Additionally, 24 g of SJG was given three times a day to group A, and the same dosage of SJG and Smecta 15 g thrice a day was given to group B, while no additional treatment was given to the control group. The number of 5-HT+C was measured respectively before and two weeks after treatment by immunohistochemical method.RESULTSThe number of 5-HT+C decreased after treatment in all the three groups (P<0.05), but the decrement was more significant in the two test groups than in the control group (P<0.05 and P<0.01, respectively), while comparison of 5-HT+C between the two test groups showed insignificant difference (P>0.05).CONCLUSIONSJG can reduce the number of 5-HT+C in IBS patients of SGAP syndrome type, and its effect is enhanced when used in combination with Smecta.