hi my 3.5 y.o daughter has fever since ystrdy morning 38.5 and vomitted.took her to ER,no cough no ear inf and no uti , so the doctor didnt give any med, this morning she has diarrhea (4 times, but the last one was not too liquid) with light green stool,last advil syrup was at 7 am this morning,she is not too weak, just complain its hurt when she want to poo otherwise she is fine.should i go back to ER and ask for antibiotic?