Abstract
RATIONALE: Post-polypectomy perforation (PPP) is an uncommon complication, usually occurring within 24 hours of colonoscopic polypectomy. Delayed perforation beyond several days is extremely rare. PATIENT CONCERNS: A 65-year-old man underwent colonoscopic removal of a 6-mm sessile tubular adenoma in the descending colon using a hot snare. DIAGNOSES: Six hours later, he developed abdominal pain with computed tomography findings consistent with post-polypectomy electrocoagulation syndrome and improved after conservative management. Fifty-four days later, he re-presented with severe abdominal pain; computed tomography revealed free intraperitoneal air and colonic necrosis. INTERVENTIONS: Emergency subtotal colectomy confirmed PPP. OUTCOMES: The patient recovered well and remained asymptomatic at 6-month follow-up. LESSONS: This case highlights that PPP can occur several weeks after polypectomy and may initially mimic post-polypectomy electrocoagulation syndrome. Clinicians should remain alert to late complications in patients with recurrent or persistent abdominal symptoms after polypectomy.