Chronic diarrhea and intestinal spirochetosis: a case highlighting the importance of histological diagnosis. A case report.

Abstract Human intestinal spirochetosis is an uncommon cause of chronic diarrhea caused by colonic colonization by Brachyspira species. We report the case of a 56-year-old man with chronic watery diarrhea, weight loss, and occasional fecal incontinence. Laboratory tests and colonoscopy were unremarkable. Colonic biopsies and immunohistochemical analysis confirmed intestinal spirochetosis. Treatment with metronidazole led to complete symptom resolution. This case highlights the importance of considering intestinal spirochetosis in the differential diagnosis of chronic diarrhea, even in patients without risk factors or endoscopic abnormalities.