Diarrhea may be related to bacterial infection, improper diet and cold abdomen. 1. Bacterial infection: After the fever goes down, the body’s resistance is low, and a little inattention may cause bacterial infection. This can cause gastrointestinal discomfort and diarrhea. 2. Improper diet: After the fever goes down, the appetite becomes bigger, if in the process of eating, eating cold and stimulating food or unclean food, then diarrhea symptoms will occur. 3. Abdominal cold: after the fever, the body’s own resistance is reduced, if you do not pay attention to warmth, abdominal cold. It will stimulate the gastrointestinal tract, abdominal pain, diarrhea and other symptoms. In short, if the fever has been well after the diarrhea, it is recommended to go to the hospital for a systematic examination, to identify the cause of the disease, and then treated as soon as possible.