The reason for drinking milk diarrhea, consider may be lactose intolerance, allergy to milk or acute gastroenteritis. 1. There is lactose intolerance, some people have lactase deficiency, intake of lactose-containing foods, after drinking milk, diarrhea, bloating and other symptoms of indigestion, which will be more pronounced when drinking milk on an empty stomach. 2. Allergy to milk. Milk belongs to high protein food, some people are allergic to high protein food, such as milk, shrimp, eggs will be allergic to eat will produce diarrhea, cough, rash and other phenomena. People who are allergic to seafood, milk and other high-protein foods should not drink too much milk at a time, and should drink small amounts each time. 3. If the milk is expired or contaminated, or cold milk in winter to stimulate the gastrointestinal tract, may lead to acute gastroenteritis, gastrointestinal dysfunction, manifested as diarrhea, abdominal pain and other symptoms. Drinking milk diarrhea is recommended to consult a doctor in time to clarify the cause of the disease, for treatment.