Colonic duplication with heterotopy of gastric mucosa.

Gastrointestinal duplications are rare congenital anomalies, occurring in 1/5000 livebirths [1,2]. However, colonic duplications are extremely rare with only 7% of duplications involving the colon [3]. Heterotopy of gastric mucosa is a congenital lesion that often accompanies intestinal duplication [4]. In the case of symptomatic duplications, surgery is the treatment of choice, especially when complicated by ileus or hemorrhage [5]. Here we present an unusual case of largebowel duplication in a patient with chronic diarrhea. A 48-year-old man having four to six motions daily was seen in the outpatients clinic. On examination, infection was excluded and Crohn’s disease was suspected. The patient was referred to the gastroenterology department. Routine blood tests did not reveal any abnormalities. Esophagogastroduodenoscopy showed longitudinal ulceration at the duodenal bulb. Histological examination revealed chronic unspecific duodenitis with foci of granulation tissue but no granulomas. Following these investigations, a colonoscopy was done, which revealed an unusual presentation of the large intestine. A structure seen at the outer edge of the anus seemed like the orifice of a perianal fistula. At the start of the procedure, the colonoscope was inserted into the descending colon, where a double distal lumen was observed (●" Fig.1a). The colonoscope was inserted first into the right lumen and, then into the left one, and each time it reached the cecum and terminal ileum. In the cecum, the scope was retroflected, revealing a proximal double lumen (●" Fig.1b). Along with colonic duplication,mucosal changes including edema, nodulation, and salmon-like color were also noted (●" Fig.1c). Microscopically, extensiveheterotopyof the gastric mucosa was observed (●" Fig.2). To identify precisely the extent of the duplication, barium enema was carried out (●" Fig.3). As a perianal fistula was suspected, transrectal ultrasound examination was also done (●" Fig.4). Prior to this report, a likely association between Crohn’s disease and large-bowel duplication has not been described.