If the patient has diarrhea and body aches, the first thing to consider is gastrointestinal flu. Ask the patient if he has fever, sore throat, runny nose, sneezing and other flu symptoms. If the patient does not have cold symptoms, but only has diarrhea and body aches, it is likely to be acute gastroenteritis, which requires routine stool tests and blood tests for clarification. When the diarrhea is heavy, it will cause excessive loss of water and electrolytes, which needs to be replenished with fluids in time.