Objective To study the effect of prevention and treatment for patients with radiation proctitis by retention enema.Methods According to the digital table,120 patients with pelvic tumor treated with radiotherapy were randomly divided into two groups.The observation group was taken retention enema 2 to 14 days after radiotherapy once a day.The control group was taken retention enema when the patients with radiation proctitis after radiotherapy.The severity and frequency of radiation proctitis were observed in the two groups.Results The incidence of radiation proctitis in the observation group was 35.0％,which was significantly lower than that of the control group (83.3％) (χ2 =47.623,P =0.000).The severity of radiation proctitis was also significantly lower than that of control group.The incidence of Ⅱ and Ⅲ degree of radiation proctitis in the observation group were 3.3％,0,respectively,which were significantly lower than those of the control group (26.7％,6.7 ％) (χ2 =12.810、4.138,P =0.000、0.042).The total efficiency rate was 100.0％,which was significantly higher than that of the control group (72.0％)(χ2 =32.558,P =0.000).Conclusion Retention enema can effectively treat the radiation proctitis and the effect will be more significant if the retention enema starts soon after radiotherapy.