Preventive Efficacy of Bergmann Enema for Acute Radiation-induced Rectal Injury in Rectal Cancer Patients Undergoing Short-course Radiotherapy

Inclusion Criteria: 1. Aged 18 to 75 years, regardless of gender; 2. Fully understand this study and voluntarily sign the informed consent form, able to comply with the study protocol and complete all trial procedures; 3. Patients with pathologically confirmed mid-lower rectal cancer; 4. Undergoing short-course pelvic radiotherapy (total dose of 25-35Gy in 5.0-7.0 fractions over 5 consecutinve days); 5. Eastern Cooperative Oncology Group (ECOG) score of 0-1, with an expected survival time of more than 6 months; 6. Assessment by the attending physician and researcher indicates that vital organ function can tolerate the treatment risks. Exclusion Criteria: 1. Severe comorbidities, including uncontrolled stable medical diseases after treatment, or a history of neurological or psychiatric disorders (such as dementia or epilepsy), making them unsuitable for radiotherapy; 2. Patients who have received pelvic radiotherapy; 3. Presence of malignant pleural effusion or malignant abdominal effusion, or accompanied by bowel obstruction; 4. Pregnant or breastfeeding women; 5. Patients expected to undergo major surgery during the study period; 6. Participation in other clinical trials within 4 weeks prior to enrollment; 7. A history of alcohol abuse, drug use, or substance abuse within the past year; 8. Severe allergic constitution, or allergy to Bergmann; 9. Inability to cooperate with the enema; 10. Subjects deemed unsuitable for participation in this trial for other reasons by the researcher.