Author: Peter Bakes, M.D. Educational Pearls Chronic diarrhea is defined as 3 or more loose, watery stools lasting more than 2-3 weeks. Look for clues in the history, including  travel (could suggest infectious etiology), antibiotic use (could suggest C. Diff), and family history. Irritable Bowel Disease (Crohn’s/Ulcerative Colitis) is an autoimmune disorder that affects 1.3 million Americans and is a leading cause of chronic diarrhea. Crohn’s always involves the terminal ileum, but can present anywhere along the GI tract. It causes transmural inflammation of the bowel wall and can lead to adhesions, perforations, and fistulas. Ulcerative colitis usually involves the rectum and causes mucosal inflammation only. Workup for IBD includes colonoscopy and tissue biopsy. Treatment for IBD includes dietary changes, 5-ASA/Mesalamine, steroids, and infliximab (anti-TNF alpha). References:  https://www.aafp.org/afp/2011/1115/p1119.html