Chronic diarrhea. A. Initial management based on accompanying symptoms or features. B. Evaluation based on findings from a limited age-appropriate screen for organic disease. Alb, albumin; BM, bowel movement; Hb, hemoglobin; IBS, irritable bowel syndrome; MCH, mean corpuscular hemoglobin; MCV, mean corpuscular volume; OSM, osmolality; pr, per rectum. (Reprinted from Camilleri M et al: Pathophysiology, evaluation, and management of chronic watery diarrhea. Gastroenterology 152:515, 2017.)