The symptoms of fever with vomiting and diarrhea may be caused by the following factors: 1. In adults, fever with vomiting and diarrhea is usually caused by eating spoiled food or unclean food that leads to acute gastroenteritis, as well as symptoms such as urgency and abdominal pain. 2. The child may be infected with rotavirus, which causes viral enteritis. The stool may be watery or egg-flower-like, or it may be due to indigestion caused by the child eating food that is too difficult to digest or over-eating. It is recommended that patients with fever accompanied by vomiting and diarrhea go to the hospital for routine stool examination in a timely manner to clarify the cause and then use medication to avoid electrolyte disorders and dehydration.