Differential Diagnosis of Chronic Watery Diarrhea
Chronic Watery Diarrhea can be subdivided in: osmotic, secretory and functional. Secretory Diarrhea:: bowel secretes too much fluid VERY HIGH volume stools (>1L) Stool Osmolar Gap less than 50. No changes on Fasting. Caused by enterotoxins, bile acids(when ileal resection), carcinoid sx, VIPoma. Osmotic Diarrhea:: Non absorbable solutes that stay in bowel and drag water in its SMALLER volume stools. (<1L) Stool Osmolar Gap more than 50. Stops on fasting. ex. lactose intolerance and celiac disease Functional Diarrhea:: IBS, where hallmark is hypermotility, has smaller volume and symptoms disappear at night.