Clinical Observation of Drug Retention Enema in Preventing Acute Radiation-induced Rectal Injury

Inclusion Criteria: * There are clear indications for radiotherapy (pelvic radiotherapy or rectal radiotherapy) according to relevant guidelines; * ECOG score 0-1; * normal mind, clear consciousness; * High compliance; * Able to cooperate with the interviewer Exclusion Criteria: * Poor compliance, unwilling to participate or unable to cooperate with the interviewer; * Patients with other intestinal diseases (such as Crohn's disease, rectal ulcer, anal fissure, anal fistula, hemorrhoids, etc.) and perianal diseases; * serious heart, brain, liver, kidney disease; * Long-term immune dysfunction; * Pregnant or lactating women; * Patients who terminate treatment for various reasons.