Hello, There are many causes of fever with abdominal pain in children. Gastoenteritis, is a inflammation of intestine and the stomach, is the most common cause of fever with abdominal pain in children. Urinary tract infection, in which patient complain with frequent urination or burning micturition with fever. Appendicitis, a low grade fever with nausea or vomiting is common in appendicitis. Pneumonia, an infection of lungs which shows fever and may cause abdominal pain, Intestinal T.B, cause low or sometimes high grade fever with abdominal pain. Abcess,irritable bowel syndrome, inflammatory bowel disease, influenza, lactose intolerance, diverticulosis, intestinal ileus, Giardiasis, crohns disease, hepatitis A or B, kidney infection, drug overdose and reaction, Typhoid fever, mesentric lymphadenitis. To rule out the exact cause get some blood test, ultrasound scan and X ray. Hope I have answered your query. Let me know if I can assist you further. Regards, Dr. Ankur