There are many causes of fever and left side of the abdomen pain, such as cold, enteritis, intestinal spasm, etc. According to the cause of the disease, choose different methods of treatment. 1. Cold: may be due to the weather temperature is relatively low, or intake of too much cold food, such as ice cream, cold drinks, etc., the child’s gastrointestinal resistance is relatively low, thus causing abdominal pain, fever, usually pay attention to warmth, the temperature is low in a timely manner to add clothing, you can relieve the symptoms. 2. enteritis: may be due to viral infection, bacterial infection, not pay attention to hygiene, or eat unclean food can cause enteritis, abdominal pain, fever, vomiting symptoms, it is recommended to take medication under the guidance of a doctor, such as montelukast, etc., can relieve the symptoms. 3. Intestinal spasm: It may be caused by eating cold or irritating food, or food with bacterial infection, which will cause intestinal spasm, paroxysmal pain in the abdomen, vomiting, nausea, etc. You can take medication under the guidance of a doctor, such as atropine tablets, etc., which can effectively relieve the symptoms. If the symptoms have not been relieved, it is recommended to go to the hospital for examination and treatment.