Hi Thanks for posting your query on HCM I have read and understood your concern There are many medical conditions that may cause his symptoms.Possible causes may include: -Chronic digestive conditions like Crohn s disease, ulcerative colitis, celiac disease, microscopic colitis and irritable bowel syndrome -Digestive viral, bacteria or parasitic infections -Lactose intolerance -Artificial sweeteners I will advise you see a Gastroenterologist for examination and tests.Tests that may help include: stool exam/culture, abdominal ultrasound and/or CT scan, colonoscopy and if need be, other tests may be requested.The management of his condition will depend on underlying cause.In the meantime, i will advise he tries the following: *Take enough fluid(water) to replace fluid losses *If diarrhea too frequent, he may take an anti-diarrheal like imodium *If vomiting persist, an anti-emetic like vogalene may help. *I will also advise that his blood sugar should be regularly checked since he quitted taking metformine Hope this will help.You may write back if more concerns Best regards Dr Mbuomboh