Objective To investigate the therapeutic effect of Tongxiening Granules combined with Otilonium Bromide Tablets in treatment of diarrheal irritable bowel syndrome.Methods Patients(80 cases)with diarrheal irritable bowel syndrome in Qinhuangdao Beidaihe Hospital from June 2021 to May 2023 were divided into control and treatment groups according to the random number table,and each group had 40 cases.Patients in the control group were po administered with Otilonium Bromide Tablets,1 tablet/time,three times daily.Patients in the treatment group were po administered with Tongxiening Granules on the basis of the control group,1 bag/time,three times daily.Patients in two groups were treated for 4 weeks.The clinical efficacies,the symptom disappearance time,diarrhea symptoms,and serum indicators in two groups were compared.Results After treatment,the total effective rate of the treatment group was 95.00%,while the total effective rate of the control group was 75.00%,with a significant difference between the groups(P<0.05).After treatment,the disappearance time of abdominal pain,diarrhea,and abdominal distension in the treatment group was shorter than that in the control group(P<0.05).After treatment,the scores of defecation frequency and stool trait in two groups were lower than those before treatment(P<0.05),and the scores of defecation frequency and stool trait of the treatment group were lower than those of the control group(P<0.05).After treatment,the serum levels of CCL-16 and IL-17A were lower than before treatment,but the serum levels of IL-12 were higher than before treatment(P<0.05).The serum levels of CCL-16 and IL-17A in the treatment group were lower than those in the control group,but the serum levels of IL-12 were higher than those in the control group(P<0.05).After treatment,the serum levels of DAO and D-LAC were lower than those before treatment(P<0.05),and the serum levels of DAO and D-LAC in the treatment group were lower than those in the control group(P<0.05).Conclusion Tongxiening Granules combined with Otilonium Bromide Tablets can significantly improve the therapeutic effect in patients with diarrheal irritable bowel syndrome,further reduce the inflammatory response and intestinal barrier function damage.