Low grade (upto 100) fever in evening from past 3 days. Flatulence, acidity and no appetite at all no other symptoms, antacid reduces fever, any advice?

Symptoms. You may be having an infection, not sure what kind by your description. Push fluids, go with blend foods for now and take Acetaminophen if fever if over 101.5 or having symptoms of pain in the body. If fever continues and your conditions doesn't get better or gets worse, see doc.