A Case of Diversion Colitis Successfully Treated by Synbiotic Stimulation via the Efferent Limb

Diversion colitis (DC) is an inflammatory condition that develops in a bowel segment excluded from the fecal stream after colostomy or ileostomy. We report a case of symptomatic DC successfully treated with synbiotic stimulation via the efferent limb of an ileostomy. A 75-year-old man underwent endoscopic mucosal resection (EMR) for a transverse colon polyp. During the procedure, thermal injury caused a perforation at the splenic flexure, necessitating emergency partial resection of the transverse colon, including the perforated site, and creation of an ileostomy. Two weeks after surgery, the patient developed recurrent hematochezia. Colonoscopy revealed severe mucosal atrophy and friability predominantly in the excluded right colon, leading to a diagnosis of DC. Because the inflammatory changes were more prominent in the right colon, synbiotic stimulation was administered anterogradely via the efferent limb of the stoma. Follow-up colonoscopy performed 1 month later demonstrated marked improvement in the mucosal findings. The patient subsequently underwent stoma closure, and the postoperative course was uneventful. This case suggests that synbiotic stimulation via the efferent limb may be an effective treatment option for symptomatic DC and may improve the condition of the excluded bowel before stoma closure.