Perforated Ileal Diverticulitis Presenting With Acute Peritonitis in an Elderly Patient: A Case Report.

Ileal diverticulitis is an uncommon cause of acute abdomen, and perforation is a rare but serious complication that may lead to secondary peritonitis. Its clinical presentation is often nonspecific and may mimic more common intra-abdominal emergencies, making computed tomography (CT) essential for diagnosis. We report the case of a 79-year-old man who presented with a three-day history of diffuse abdominal pain, nausea, vomiting, inability to tolerate oral intake, and absence of bowel movements and passage of flatus. Physical examination revealed abdominal distension, diffuse tenderness, guarding, and signs of peritoneal irritation. Laboratory studies showed mild leukocytosis and markedly elevated C-reactive protein. Contrast-enhanced CT demonstrated multiple ileal diverticula, segmental bowel wall thickening, inflammatory changes, pneumoperitoneum, and an adjacent fluid collection, consistent with perforated ileal diverticulitis and secondary peritonitis. Exploratory laparotomy revealed multiple ileal diverticula involving approximately 50 cm of the distal ileum, purulent and enteric contamination, and a perforated ileal diverticulum measuring approximately 5 mm. Segmental ileal resection with creation of an end ileostomy was performed. Histopathological examination confirmed acute diverticulitis with diverticular perforation and no evidence of malignancy. The patient had a favorable postoperative course and was discharged on postoperative day 7. This case highlights the importance of considering ileal diverticulitis in elderly patients with acute peritonitis and emphasizes the role of CT and timely surgical management in complicated cases.