Anastomotic-Transverse Colon Fistula Following Gastrectomy: A Case Report of Delayed Diagnosis 14 Years After Surgery.

BACKGROUND Gastrocolic fistula is a rare complication of partial gastrectomy that can present with weight loss, diarrhea, and feculent vomiting. Most cases documented in the literature have occurred following non-physiological anastomoses, such as Billroth II procedures. This report describes the case of a 60-year-old man with a gastrocolic fistula from the gastrectomy anastomosis to the transverse colon 14 years after a Billroth I (gastroduodenal) anastomosis. CASE REPORT A 60-year-old male patient presented with a 6-year history of recurrent diarrhea, which had worsened over the past 6 months and was accompanied by weight loss. Fourteen years prior, he had undergone a subtotal gastrectomy with Billroth I anastomosis for gastric perforation. Ultimately, meticulous combined gastroscopy and colonoscopy revealed the presence of a fistulous opening and colonic mucosa, establishing a diagnosis of gastrocolic fistula. Following comprehensive preoperative nutritional support, the patient underwent laparoscopic resection of the fistula tract and the affected gastric and colonic segments, with concomitant gastrointestinal reconstruction. Postoperatively, the patient recovered smoothly, with complete resolution of diarrhea symptoms and marked improvement in nutritional status. CONCLUSIONS This case highlights that gastrocolic fistula can present as an extremely late complication following gastrectomy, even after an anastomosis performed using the more physiologically approximating Billroth I technique. Clinicians should exercise heightened vigilance with patients with a history of gastric surgery (regardless of procedure type) presenting with unexplained chronic diarrhea. Proactive use of direct examination methods, such as endoscopy, is essential to prevent misdiagnosis of this rare yet curable condition.