The phenomenon of diarrhea and vomiting at the same time is mainly caused by the following reasons: 1. symptoms of indigestion, due to unclean diet or eating too much, triggering the symptoms of spasm of the stomach and intestines, eventually leading to abdominal pain, diarrhea, abdominal distension, as well as nausea, vomiting phenomenon. 2. symptoms of abnormal intestinal function caused by electrolyte disorders in the body, low potassium and hyponatremia can easily lead to electrolyte disorders in the body, thus bringing adverse effects on the digestive system. 3. The symptoms of food poisoning can be caused by unclean food or meat that is out of date or undercooked, which can lead to vomiting and diarrhea. 4. In addition to the symptoms of vomiting and diarrhea, these diseases are also likely to cause a series of systemic symptoms such as fever and weakness of the limbs.