My 9 months old son has a fever again and is throwing up his medicine that the dr gave him. should i go to the emergency room again ?

Fever: You dont let us know how high the childs temperature is or what medicine the doctor gave you. You can give your child pedialyte for his vomiting, put him in a warm tub to bring his fever down and you can get fever suppositories to bring his temp down. If all else fails take him to the er.

Yes, needs a recheck: You son may be dehydrated, needs a recheck, if dehydrated, IV fluids, IV anti nausea meds.