Yesterday Early Morning My Six Yr Son Started Vomiting He

Yesterday early morning my six yr son started vomiting he vomited 3-4 times, in a hour or two hrs.lastly in his vomiting i can observe thick saliva and yellowish dark liquid.Later in morning i got ondem liq and gave him 5 ml he relaxed and slept.but he was weak an not taking food.again in afternoon i repeated ondem.he was sleeping but in the evening he got fever about 100 deg f.I gave him crocin,nutralin B tab.after ondem.He felt better and had some biscuits and popcorn.He slept sound in the night.Now what should i do he is feeling good but complaining a bit small pain in the abdomen.and not ready to have reg food.