Drinking water in the morning on diarrhea may be caused by gastrointestinal dysfunction, may also be irritable bowel syndrome, enteritis and other diseases. 1. Gastrointestinal dysfunction: patients drink water in the morning on an empty stomach, due to the early morning has not eaten, this time to drink water may stimulate the gastrointestinal tract to accelerate intestinal peristalsis, gastrointestinal dysfunction, which leads to diarrhea. 2. Irritable bowel syndrome: the etiology and pathogenesis of irritable bowel syndrome are not yet clear, and it may be the result of bowel-brain interaction. Patients may manifest diarrhea, mostly in the morning or after meals, patients also have abdominal pain, constipation and other symptoms. 3. Enteritis: enteritis is mainly due to bacterial, viral and other pathogenic infections, as well as immune abnormalities and other factors, the patient will have diarrhea, abdominal pain, bloody stools, nausea and other symptoms, which can also lead to diarrhea in the morning with a glass of water. When patients have symptoms of diarrhea when drinking water in the morning, it may be caused by gastrointestinal dysfunction, which does not require special treatment, and it is recommended to drink warm water or drink water after eating. If it is caused by disease, the patient should consult a doctor in time, and follow the doctor’s instructions for treatment.