Gastritis for 20 days. Should we do?

Child was having high fever, 103+ on 8july 2018. Sore throat was found. Ibugesic plus, alex plus was suggested for 3 days. No improvement in high temp, so antibiotic augmentin was suggested after that. Note that during this period, child was complaining of stomach ache on & off. With antibiotic, fever came down to 99+. But same night, child started having terrible stomachache. So bad, she was not able to sleep whole night. She kept waking up every half an hour, burping heavily. Doctor stopped Ibugesic & changed antibiotic too. Jr lanzol was given. Child suffered with too much pain for 3 days. She recovered in next 5-6 days. But since 25 july, child is again complaining of stomachache. Jr lanzol is going for 3 days but not much improvement. Her stomach is bloated. Today she passed mucus also(no stool, only mucus). What should we do? Please help.