Hello, As per my clinical experience, tummy discomfort with loss of appetite and high grade fever with sweating indicates underlying GI infection most likely. The primary relief with anti-pyretic as acetaminophen or paracetamol syrup or dispersible tablet and later on pediatrician consultation is a must for necessary prescription of GI specific antibiotics to cover the infection better way. Till that time, allow him plenty of liquids including oral re-hydration salt, offer rice, curd and butter milk for GI flora support. Hope I have answered your query. Let me know if I can assist you further. Regards, Dr. Bhagyesh V. Patel, General Surgeon