Abstract：Objective：To observe the curative effect of retention enema with modified Dachengqi tang for elderly patients with dynamic ileus caused by antipsychotic drugs. Methods：Eighty-two elderly patients with dynamic ileus who had mental disorders caused by organic brain diseases and hospitalized with oral antipsychotic drugs for more than 10 days were randomly divided into two groups. The treatment group was intervened with retention enema with modified Dachengqi tang and an oral administration of lactulose，including 42 cases. The control group was treated with oral administration of lactulose，including 40 cases. The therapeutic effect was compared between the two groups. Results：The total effective rate was 80.95% in the treatment group and 42.50% in the control group；the one in the treatment group was better than that in the control group， the difference being significant(P＜0.05). In the treatment group，the shortest time was 3 h，and the total defecation rate within 24 h was 71.43%(30/42). In the control group，4 h≤the earliest defecation time＜24 h，and the defecation rate within 24 h was 20.00% (8/40). The defecation rate within 24 h was better in the treatment group than in the control group， the difference being significant(P＜0.001). The defecation rate after a week was 19.05% in the treatment group(8/42) and 57.50% in the control group(23/40)， the difference being significant(P＜0.001). The improvement rate of score of Karnofsky Performance Scale(KPS) was 66.67% in the treatment group(28/42)， significantly better than that of 45.00% in the control group(18/40)，the difference being significant(P＜0.05). Conclusion：Based on the conventional treatment of oral administration of lactulose， the additional application of retention enema with modified Dachengqi tang for patients with dynamic ileus caused by antipsychotic drug，can alleviate the patient's symptom in time and is helpful to improve their quality of life.