Patients with rectal cancer who undergo radical resection with protective loop ileostomy may experience diversion-related changes in the distal bowel, gut microbiota dysbiosis, diversion colitis, and impaired bowel function after ileostomy reversal. Autologous fecal microbiota transplantation may help restore the intestinal microbial environment in the defunctioned bowel and improve postoperative bowel function.
In this study, eligible patients will undergo standard radical rectal cancer surgery with protective loop ileostomy. At approximately 8 weeks after surgery, patients without severe postoperative complications such as anastomotic leakage will undergo anal swab sampling for 16S rRNA gene sequencing. Autologous fecal microbiota transplantation will be performed once weekly at postoperative weeks 8, 9, 10, and 11. At approximately 12 weeks after surgery, colonoscopy will be performed to evaluate the distal bowel mucosa, and intestinal secretion samples will be collected for 16S rRNA gene sequencing. Ileostomy reversal will then be performed according to routine clinical practice. Bowel function will be followed for 3 months after ileostomy reversal, with the primary endpoint being the LARS score at 3 months after reversal.