Firstly,give light meals more frequently,including curd and Banana in the diet.use syp ondem for vomiting half hour before meals,and syp anafortan for stomach ache. Use paracetamol for fever and repeat every 4 hours if required. Add Enterogermina vial one vial twice a day for 5 days. If not improving OR accompanied by other symptoms like dullness or fever or refusal to feed,consult your paediatrician.