Outcomes of Subtotal Colectomy with Ileorectal Anastomosis and Regular Colonoscopic Surveillance of Polypectomy in Patients with Familial Adenomatous Polyposis

Background Familial adenomatous polyposis (FAP) is an inherited disorder caused by mutations in the adenomatous polyposis coli gene, causing numerous colorectal adenomas to develop. If left untreated, FAP is associated with a nearly 100% lifetime risk of colorectal cancer. Subtotal colectomy with ileorectal anastomosis (IRA) is a surgical option that preserves rectal function but necessitates intensive postoperative surveillance due to the residual risk of malignancy in the retained rectum. Methods This retrospective study included seven patients with FAP who underwent subtotal colectomy with IRA at a single institution between 2015 and 2024. Postoperative management involved intensive colonoscopic surveillance and polypectomy of rectal lesions. Clinical and pathological data were analyzed, including the incidence of residual rectal polyps, bowel function, and clinical outcomes. Results All patients developed residual rectal polyps during follow-up, which were successfully removed through polypectomy without evidence of malignant transformation. Bowel function was well-preserved in all patients, with rectal lengths ranging from 10 to 15 cm. Silymarin, a natural polyphenolic flavonoid with potential chemopreventive effects, was administered to six of the seven patients, among whom it was well-tolerated. The long-term effects of silymarin are under evaluation during ongoing follow-up. Conclusion Subtotal colectomy with IRA, combined with regular colonoscopic surveillance and timely polypectomy, can effectively manage FAP and preserve bowel function. Silymarin may be a promising adjunctive chemopreventive agent; however, further clinical trials are needed to validate its efficacy and safety in human populations. These findings highlight the necessity of individualized surgical planning and vigilant long-term surveillance in FAP management.