Abstract： Objective： To observe the clinical effect of self- made Huokou Liqi Chushi Decoction for diarrhea- predominant irritable bowel syndrome (IBS- D) and its effect on intestinal barrier function and gastrointestinal hormone levels. Methods：A total of 89 cases of IBS-D patients were randomly divided into the control group and the observation group，with 44 and 45 cases in each group respectively. The control group was given the oral administration of Pinaverium Bromide Tablets， and the observation group was treated with Huokou Liqi Chushi Decoction. After 4 weeks of treatment，the changes in traditional Chinese medicine syndrome scores，levels of D- lactic acid，diamine oxidase (DAO)，gastrin (GAS) and calcitonin gene- related peptide (CGRP) in serum， and scores of irritable bowel syndrome- related Quality of Life Scale (IBS-QOL) before and after treatment as well as the clinical effects were compared between the two groups. Results：The total effective rate was 93.18% in the observation group and 77.78% in the control group， the difference being significant (P＜0.05). After treatment， the scores of syndromes like sudden diarrhea after abdominal pain， abdominal cold- pain， soreness and weakness of waist and knees， poor appetite and cold body and limbs as well as the total scores in the two groups were decreased when compared with those before treatment (P＜0.05)， and the above scores in the observation group were lower than those in the control group (P＜0.05). After treatment， the levels of D- lactic acid and DAO in serum in the two groups were decreased when compared with those before treatment (P＜0.05)，and the levels of D- lactic acid and DAO in the observation group were lower than those in the control group (P＜ 0.05). After treatment，GAS levels in the two groups were decreased when compared with those before treatment (P＜0.05)， and CGRP levels were increased when compared with those before treatment (P＜ 0.05)；GAS level in the observation group was lower than that in the control group (P＜0.05)，and CGRP level was higher than that in the control group (P＜0.05). After treatment， IBS- QOL scores in the two groups were increased when compared with those before treatment (P＜0.05)，and the IBS-QOL score in the observation group was higher than that in the control group (P＜0.05). During the treatment，there were no obvious abnormalities in blood and urine routine as well as liver and kidney function between the two groups. Conclusion：Huokou Liqi Chushi Decoction for IBS- D patients has a definite curative effect，and can effectively regulate gastrointestinal hormone levels，improve intestinal barrier function，improve clinical symptoms and enhance the quality of life of patients.