Surgical treatment of giant colonic diverticulum with sigmoidovesical fistula, case report and literature review.

Introduction and importance: Diverticular disease is increasingly prevalent. Giant colonic diverticulum (GCD) is an extremely rare but potentially serious complication of diverticular disease. Although uncommon, prompt diagnosis and treatment are essential to prevent severe complications. Typical symptoms include abdominal pain and fever. Diagnosis is primarily achieved through computed tomography (CT). Surgical resection of the affected colonic segment with primary anastomosis represents the mainstay of treatment. This case report aims to describe a GCD complicated by a sigmoidovesical fistula and to review the relevant literature. Case presentation: We describe a rare case of a GCD complicated by a sigmoidovesical fistula. The clinical presentation was misleading, mimicking a urinary tract infection (UTI) rather than diverticular disease. Surgical management consisted of sigmoidectomy with primary anastomosis and closure of the bladder fistula. The postoperative course was uneventful, and the patient remains asymptomatic at follow-up. Discussion: The pathogenesis of GCD remains unclear. The most widely accepted hypothesis is the "ball-valve" mechanism, whereby intermittent occlusion allows air to enter the diverticulum without egress, leading to progressive enlargement. Treatment options range from conservative management to diverticulectomy or segmental colectomy, with surgical resection generally recommended due to the risk of complications. Conclusion: GCD is an extremely rare condition. Although the optimal therapeutic approach has not been definitively established, surgical resection remains the most widely accepted treatment. In elderly patients presenting with recurrent UTIs, early imaging should be considered to exclude a colovesical fistula in the setting of diverticular disease or, more rarely, GCD.