My Son Is 6 Yrs Old. He Was Vomitting. So

My son is 6 yrs old. He was vomitting. So prescribed ondem 4mg bd.vomitting was contrlled but wen I discontinued ondem after 2 days he had another epidode. So having ondem again.then he had 1 episode of fever. Gave oflox forte fr 3 days. Urine no growth. Also lanzol 15mg tab. Vitazyme syp. Its been 7 days. No vvomiting now. But now loose stool. Wat to do ? Is it a side effect?