S3671 Post-Polypectomy Syndrome Presenting With Sepsis-Like Symptoms: A Rare Complication Mimicking Diverticulitis

Introduction: Post-polypectomy coagulation syndrome (PPCS) is an uncommon complication following colonoscopic polypectomy, resulting from thermal injury to the colonic wall without frank perforation. It may mimic diverticulitis or perforation, presenting with abdominal pain, leukocytosis, and low-grade fevers. Awareness is crucial to avoid unnecessary surgical interventions. Case Description/Methods: A 73-year-old woman with a history of left renal cell carcinoma (s/p resection in 2022), gastroesophageal reflux disease, and sigmoid diverticulosis presented to the Emergency Department 1 day after outpatient colonoscopy, due to 4 sessile polyps were removed, including a 10 mm sessile polyp in the ascending colon resected using hot snare cautery. She developed progressive right lower quadrant abdominal pain, subjective fevers (Tmax 101°F), and chills. On presentation, she was hemodynamically stable with localized tenderness. Laboratory evaluation revealed leukocytosis and hemoglobin of 11.1 g/dL. computed tomography abdomen/pelvis demonstrated new pericolic fat stranding around the ascending colon without free air or fluid collection, raising concern for post-polypectomy coagulation syndrome (PPCS) versus acute diverticulitis or microperforation. She was empirically started on IV fluids, piperacillin-tazobactam, and antipyretics. Blood cultures remained negative. The patient defervesced and improved clinically with supportive care alone. Serial abdominal exams remained benign, and no signs of peritonitis developed. She was discharged in stable condition with outpatient gastroenterology follow-up. Discussion: PPCS is thought to result from transmural thermal injury during electrocautery, leading to localized peritonitis without overt perforation. Risk factors include larger polyp size, nonpedunculated morphology, and use of electrocautery in the right colon, where the wall is thinner. This case highlights the importance of differentiating PPCS from diverticulitis or perforation, as misdiagnosis can lead to unnecessary surgery or prolonged antibiotic use. Supportive care, serial exams, and close monitoring are often sufficient for recovery. With increasing colonoscopy screening, awareness of PPCS is vital among hospitalists and gastroenterologists.