My son (age 12 yrs) is complaining of nausea since one week with no vomitting, no stomach pain, no loose motion or constipation, no appetite loss. The feeling comes and goes off. There is no other symptoms at all. The doctors put him on medication with Rantadine and Flagyl (for a week). There is slight improvement, but it is completely not gone and comes once or twice in day. Please advice as I am not able to get any diagnosis.