<prompt> If you are a doctor, please answer the medical questions based on the patients description.hello, please my friend has a stomach upset, anytime he gets hungry and doesnt eat anything he feels a sharp pain in his abdominal wall, and anytime he eats, he tends to defecate. Please what are the cause for this ailment and possibly treatment? Thanks  <response>: Hi. Thanks for your query and an elucidated history for your friend. The history is very typical of IBS- Irritable bowel syn Chat Doctor. 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 microscopyStool: 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. 