Drinking milk on an empty stomach may cause diarrhea because the milk is too cold, and generally no special treatment is needed. It may also be caused by lactose intolerance, indigestion and other diseases, which can be treated with medication for the cause. 1. Milk is too cold: milk is too cold, may stimulate the mucous membrane of the gastrointestinal tract, leading to diarrhea symptoms. Generally, no special treatment measures are needed. Paying attention to the moderate temperature of milk and eating less indigestible food can generally relieve the symptoms. 2. Lactose intolerance: drinking milk on an empty stomach diarrhea may also be caused by lactose intolerance. Patients can take probiotic preparations, such as bifidobacteria, lactobacillus, under the guidance of the doctor, can delay gastric emptying speed, slow down the intestinal operation time, increase intestinal absorption, is conducive to reducing symptoms. 3. Indigestion: drinking milk on an empty stomach diarrhea may also be caused by indigestion. Patients can follow the doctor’s instructions, take domperidone, mosapride, itopride and other drugs to promote gastrointestinal power class, to promote gastrointestinal absorption, reduce the feeling of fullness after meals. Drinking milk on an empty stomach has many other causes of diarrhea, it is recommended to go to the regular hospital, under the guidance of the doctor, the relevant examination, clear cause, symptomatic take relevant treatment measures.