Fecal Microbiota Transplantation in the Treatment of Major LARS

Inclusion Criteria: \- Age ≥ 18 years old, regardless of gender; Patients with rectal cancer who have undergone total mesorectal excision (TME) and sphincter-preserving surgery, and the postoperative period is more than 3 months; Patients with a LARS score of 21 to 42; Eastern Cooperative Oncology Group (ECOG) performance status score of 0 or 1; Expected survival period ≥ 1 year; Voluntarily sign a written informed consent form. Exclusion Criteria: \- Patients with pre-operative symptoms of fecal and urinary incontinence; Patients who have undergone pelvic surgery or LAR due to non-cancerous reasons; Patients who have undergone pelvic radiotherapy; Patients with prophylactic ostomy; Patients who have used any antibiotic medication, probiotic products, or prebiotic products in the past 4 weeks; Patients who have regularly used laxatives in the past two weeks; Pregnant or lactating women; Human immunodeficiency virus (HIV) positive; Known history of active pulmonary tuberculosis (TB). Subjects suspected of having active TB require chest X-ray, sputum examination, and exclusion based on clinical symptoms and signs; Untreated patients with chronic hepatitis B or HBV carriers with HBV DNA exceeding 500 IU/mL, or patients with active hepatitis C should be excluded. Non-active HBsAg carriers, treated and stable hepatitis B patients (HBV DNA \< 500 IU/mL), and cured hepatitis C patients can be enrolled. For subjects with positive HCV antibodies, only those with negative HCV RNA test results are eligible to participate in the study; Known history of psychiatric drug abuse, alcoholism, and drug abuse; Patients with cognitive impairment; Any situation where the investigator believes the participant should be excluded from the study.