my 4 year daughter has been vomiting and having diarrhea one night a week for 4 weeks now. Last week we took her to emergency room because she was vomiting every 20-30 mins. they gave her anti nausea meds. iv of fluids and sent her home. They said all tests were normal although her white blood cell count was elevated. Last night we had a repeat of last Wednesday. Do I head back to the er and what could be causing this? She has always been healthy until now.