Diarrhea after heavy sweating may be caused by heat stroke, gastrointestinal flu, bacterial gastroenteritis and other reasons. 1. Heatstroke: When the patient has a heatstroke, the body temperature will rise, and the body temperature regulation center will be disturbed, so that the body adopts the way of sweating to dissipate heat. At the same time, the water-electrolyte balance is also broken, which will make the intestinal mucosa stimulated, resulting in diarrhea. 2. Gastrointestinal flu: when the patient consumes too much ice cream and chilled drinks in hot weather, it will lead to gastrointestinal dysfunction causing gastrointestinal flu, which may be accompanied by abdominal pain and sweating. The increase of intestinal peristalsis leads to water and nutrients can not stay in the body, resulting in diarrhea after a lot of sweating. 3. Bacterial gastroenteritis: when the patient’s diet is not clean, it will cause bacteria to invade the body, resulting in damage to the intestinal mucosa, and a large amount of water can not be absorbed by the body, and it will be discharged from the body by way of secretion. Patients often have abdominal pain, and in severe cases, it will be accompanied by sweating and other manifestations. After abdominal pain, patients often have the urge to go to the toilet, which can result in diarrhea after a lot of sweating. When the symptoms of diarrhea after heavy sweating occur, it is best to go to the hospital to avoid adverse consequences.