To observe the clinical effects of Buzhong Yiqi decoction in the treatment of constipation predominant irritable bowel syndrome.Methods:A total of 90 patients with constipation predominant irritable bowel syndrome (IBS) admitted in our hospital from January 2016 to December 2016 were selected and divided into treatment group and control group by random number table, with 45 cases in each group.The control group was given Bifidobacterium triple viable capsules orally, and the treatment group was treated with oral administration of Buzhong Yiqi Decoction.Both groups were treated for 8 weeks.Blood samples were collected before and after treatment to determine the substance P, plasma somatostatin (SS), neuropeptide Y (NPY).The colonic mucosal tissue was obtained by colonoscopy, and the content of protease activated receptor-2 was determined by fluorescence quantitative PCR.Results:After treatment, the total effective rate of the treatment group (88.89%) was better than that of the control group (77.78%) (P<0.05).The intestinal sensitivity of two groups were significantly improved compared before treatment (P<0.05), and the improvement of abdominal pain, abdominal distension, diarrhea score in the treatment group was significantly better than the control group (P<0.05).The serum SP content and intestinal mucosa SS expression of PAR-2 were decreased after treatment at the same time, and the level of serum NPY increased.The improvement of the treatment group was better than the control group (P<0.05).Conclusion:The treatment of Buzhong Yiqi decoction in spleen and stomach deficiency constipation irritable bowel syndrome patients can effectively improve the clinical symptoms, which is worthy of clinical use.