My Grandson Had Vomitting Wed. Evening Then Seemed Fine Until

My grandson had vomitting wed. evening then seemed fine until today. he has been laying around most of the day, hasn't wanted to eat this afternoon. We gave him tylenol around 6 pm he vomitted about an hour later, says he just wants to stay in bed. He is 5 years old and usually very active. He was being treated for an ear infection until wed. evening when the doctor said we could stop it because of the vomitting.