Diarrhea after fever usually has several causes as follows: First, infectious factors, usually infectious factors are the most common causes. For example, acute gastroenteritis and food poisoning diarrhea caused by eating unclean food or other reasons usually have diarrhea after fever, and acute appendicitis, acute pancreatitis and acute cholecystitis also have fever, followed by clinical symptoms such as abdominal pain, diarrhea, nausea and vomiting. Secondly, gastrointestinal colds may also present with fever followed by diarrhea, mostly combined with headache, nasal congestion, runny nose and other cold symptoms. Thirdly, there are also factors of gastrointestinal phytodysfunction, such as irritable bowel syndrome, when there is a fever, accompanied by clinical symptoms of diarrhea.