2719 A Rare Cause of Chronic Diarrhea: Gastrocolic Fistula

Abstract

INTRODUCTION: Gastro-colic fistula is a pathological fistulous tract usually between the stomach and the transverse colon. It is a rare presentation of both benign and malignant diseases of the GI tract. Most cases in the modern world are related to adenocarcinomas of the colon. Benign fistulas are a rarer occurrence due to advancements in the medical management of peptic ulcer disease. Here we present a case report of a benign gastro-colic fistula occurring in the setting of a prior Whipple’s surgery. CASE DESCRIPTION/METHODS: A 61-year-old male presented with chronic diarrhea associated with a 50-pound weight loss, fatigue, and weakness. His past surgical history was notable of a Whipple’s procedure done 10 years ago. A trial of lactose-free diet and a course of antibiotics did not improve his symptoms. Upon further investigations, it was revealed that patient had anemia, hypokalemia and a low albumin level. Workup was negative for celiac disease, carcinoid syndrome, gastrinomas, and therefore the patient had an endoscopy which revealed a benign gastro-colic fistula in the setting of an anastomotic pyloric ulcer eroding into the transverse colon. He was then referred for surgery following optimization of his nutritional status. DISCUSSION: A majority of cases are due to malignancy, specifically gastric cancer or transverse colon cancer, although fistulas due to benign causes have also been described. In addition, cases of gastrocolic fistula have been observed in the setting of prior gastric surgeries but the interval duration of development has been reported to be around 8 to 9 months. Patients generally present with undifferentiated symptoms like diarrhea, weight loss, abdominal pain, nausea and vomiting making the diagnosis difficult. Radiologic imaging studies such as barium enema (most sensitive test) and barium meals are the mainstay of diagnosis. Endoscopy is usually not recommended as a diagnostic tool. Endoscopy with biopsy is primarily done as part of the workup to rule out malignancy. Definitive treatment includes surgical resection. Conservative medical management such as proton pump inhibitors should be considered when surgery is contraindicated or in cases that occur in the setting of peptic ulcer disease.