The reason for wanting to vomit after drinking milk may be having lactose intolerance because the body lacks the enzyme that breaks down lactose in milk, an enzyme that causes lactose to break down and be digested in the small intestine. After entering the large intestine bacteria ferment in the large intestine producing organic acids and gases that can lead to bloating, nausea and vomiting. If you drink too much milk too fast, the patient himself has gallstone disease, which can easily induce pancreatitis gallstone disease, and also symptoms of nausea and vomiting after drinking milk. In addition, lactose intolerance in the case of lactose can not be directly absorbed by the body, milk needs to digest the role of lactase can be absorbed, no direct digestion of lactose into the large intestine, stimulating gastrointestinal motility, resulting in the symptoms of wanting to vomit. Usually it is best to choose the method of drinking milk gradually, the intake of staple foods before drinking milk helps digestion, there are many reasons for wanting to vomit after drinking milk.