Iatrogenic perforation of a sigmoid diverticulum following diagnostic colonoscopy.

BACKGROUND: Colonoscopy is widely performed for diagnostic and therapeutic purposes and is generally safe. However, colonic perforation remains its most serious complication, with reported incidences ranging from 0.03% to 0.2% after diagnostic procedures. The sigmoid colon is particularly vulnerable, especially in elderly patients with diverticular disease. CASE PRESENTATION: We report the case of a 73-year-old woman with hypertension and type 2 diabetes who presented with diffuse abdominal pain 5 days after an incomplete diagnostic colonoscopy performed for chronic constipation. On admission, she was hemodynamically stable with generalized abdominal tenderness. Laboratory findings were unremarkable. Contrast-enhanced computed tomography revealed circumferential sigmoid wall thickening, a 25-mm pericolic collection, and moderate pneumoperitoneum consistent with perforated sigmoid diverticulitis. Exploratory laparotomy identified a pinpoint perforation arising from a sigmoid diverticulum with localized feculent contamination. A segmental sigmoid resection with end colostomy (Hartmann's procedure) was performed. Postoperative recovery was uneventful, and histopathology confirmed diverticulosis with focal perforation and acute inflammation, without malignancy. DISCUSSION: Iatrogenic perforation during colonoscopy is rare but potentially life-threatening. Elderly patients with diverticulosis are particularly at risk due to structural bowel wall weakness. Delayed presentation may obscure diagnosis and increase the risk of peritonitis. Computed tomography is essential for diagnosis and operative planning. Surgical management is indicated in cases of delayed recognition and fecal contamination, with resection preferred when diverticular disease is present. CONCLUSION: Early recognition, prompt imaging, and timely surgical intervention are crucial for achieving favorable outcomes in colonoscopy-related perforation.