The specific causes of fever and stomach pain in three-year-old babies are as follows: First, acute gastrointestinal inflammation caused by eating indigestible or unclean food will cause fever, vomiting and stomach pain in babies, and the symptoms of stomach pain in children can be significantly improved after vomiting, and then control the diet, and give oral gastrointestinal digestive drugs, such as gastrointestinal digestion oral solution, etc., and at the same time, according to the temperature of the child such as high fever, give oral antipyretic drugs such as acetaminophen for treatment, and give physical cooling for low fever, and the child’s symptoms can be significantly improved. Give oral antipyretic drugs, such as acetaminophen and other treatment, low fever to give physical cooling, the child’s symptoms can be significantly improved. Secondly, acute appendicitis in surgery or viral enteritis in pediatrics can cause fever, vomiting and stomach pain, which can be diagnosed according to the examination of children’s fecal tests, combined with routine blood tests, and symptomatic treatments will be given under the doctor’s detailed diagnosis and examination, for example, intravenous fluids or oral medication will be given to patients with minor cases of appendicitis, and surgery will be needed to treat serious cases. In case of viral enteritis, oral medication and symptomatic fever-reducing treatment can be given for mild cases, while intravenous fluids are needed for severe cases.