This is a prospective, observational study aimed at exploring the associations between the clinical subtypes of radiation rectal injury and prognosis. The study is planed to commence in November 2025 and prospectively observe 150 patients. During the study period, researchers will not intervene in clinical treatment decisions but will only collect patient clinical information, intestinal endoscopy/imaging/pathological data, test results, and follow-up data. The study results will fill the evidence gap in this field, advance the diagnosis and treatment of radiation-induced rectal injury, and provide scientific support for improving the prognosis of similar patients.

Inclusion Criteria:

1. 18-80 years;
2. Diagnosed with radiation rectal injury.

Exclusion Criteria:

1. Ongoing cancer therapy;
2. Tumor recurrence or metastasis.

The study population will consist of prospectively recruited adult patients clinically diagnosed with radiation rectal injury. Participants will be selected from the patient cohort at the Sixth Affiliated Hospital of Sun Yat-sen University. The inclusion criteria are: age between 18 and 80 years, and a clinical confirmation of radiation rectal injury. Patients who are currently undergoing cancer therapy or who have experienced tumor recurrence or metastasis are excluded. This study will be conducted in accordance with the Declaration of Helsinki and has been approved by the hospital's Ethics Committee. Written informed consent will be obtained from all participants prior to their enrollment.