Hi. Thanks for your query and an elucidate history for your friend . The history is very typical of IBS- Irritable bowel syndrome, the patient is hungry and the moment eats has to rush to bathroom to pass motion. This cripples him / her socially too As a precaution the following tests are done: Investigations: *Routine blood investigations like Complete blood picture, blood sugar, urea, creatinine, liver function tests, thyroid function tests. *Urine -routine and microscopy *Stool: routine, microscopy, occult blood, culture and sensitivity. *Ultrasonography of abdomen, *Colonoscopy All these investigations should be within normal limits for one to say you have IBS. Get an opinion of a Gastroenterologist and get started with proper treatment and your friend will be fine.