Giant diverticulum of the transverse colon mimicking gastrocolic fistula: A case report

INTRODUCTION: Giant transverse colonic diverticula are a rare case of giant colonic diverticulum (GCD). Instead of being asymptomatic, bleeding, inflammation, and perforation may result in fistula formation and require surgery. This type of diverticulum is thought to be closely related to the gastrocolic fistula (GCF). PRESENTATION OF CASE: We report a 26-year-old female presenting severe abdominal pain accompanied by nausea and vomiting and a history of constipation since childhood. The patient felt a mass around the epigastric region and extends to the right hypochondrium. Enema contrast examination showed a large diverticulum in the transverse colon. CT scan revealed a 21.4 × 8.4 cm structure with air-filled structures visible from the transverse colon filled with contrast material, suggesting a possible gastrocolic fistula. Resection was performed on the diverticulum and 20 cm in length of the transverse colon, followed by side-to-side anastomosis. Histopathological findings were type III GCD. The patient was discharged without complications 1 week later. DISCUSSION: Giant diverticulum is characterized by a diverticulum with 4 cm or more in length. Our case was a diverticulum from the central portion of the transverse colon with 25 × 9 × 3 cm in length and type III GCD. Resection was performed on the diverticulum and 20 cm in length of the transverse colon, followed by side-to-side anastomosis. CONCLUSION: Differentiating GCD and GCF with similar clinical course may necessitate multiple investigation before establishing the correct diagnosis. We suggest colectomy followed by side-to-side anastomosis is the best option of treatment for GCD.