To observe the clinical efficacy of Shenling Baizhu Powder combined with pinaverium bromide tablets in the treatment of diarrhea type irritable bowel syndrome (IBS-D),and to evaluate its safety.Methods:A total of 117 cases with IBS-D in Affiliated Hospital of Shandong University of Traditional Chinese Medicine from January 2013 to January 2016 were selected and randomly divided into an observation group (n=58) and a control group (n=59).The control group was treated with pinaverium bromide tablets,and the observation group was treated with Shenling Baizhu Powder on the basis of control group.Both groups were treated for 1 month.The clinical efficacy of the 2 groups was compared.The score of clinical symptom,brain-gut peptides index and rectal sensitivity index before and after treatment in 2 groups were calculated.The occurrence of adverse reaction in 2 groups during treatment was also compared.Results:The total efficiency rate of the observation group (93.10%) was higher than that of the control group (76.27%) (P<0.05); Compared with before treatment,the score of abdominal pain,abdominal distention and diarrhea as well as total score of the 2 groups were all decreased after treatment,and observation group was lower than control group (P<0.01); Compared with before treatment,the levels of serum 5-HT,VIP and SP in the 2 groups decreased after treatment,and the observation group was lower than the control group (P<0.01); Compared with before treatment,the anal canal resting pressure,rectal perception threshold,abdominal pain and defecation threshold increased after treatment in the 2 groups,and the observation group was higher than the control group (P<0.01); The adverse reaction incidence of the 2 groups (5.08%,1.72%) had no significant difference (P>0.05).Conclusion:Shenling Baizhu Powder combined with pinaverium bromide tablets in the treatment of IBS-D can relief the clinical symptoms of abdominal pain,abdominal distension and diarrhea,reduce the level of serum brain-gut peptides,improve the rectal function.The adverse reaction is less and the curative efficacy is remarkable.