What Causes Excessive Vomiting On First Day Of Menstrual Period?

Please help identify the reason for such a health situation. A girl 15 years old, during the first day when the period start is vommitting for 12 hours. Even the ER couldn't stop the vommitting with various medicine. The lab tests are ok, except the acetone is very high, leukocytes are higher than usual, and the fever is high. Moreover, pain in the abdomen, loosing consiousness, and increased convulsions. The girl is only 15 years old, didn't have any intercourse. The periods are irregular Have been to 10 different ER during the past year, and we can't find a treatment to this. Could anyone give me any advice. Have done MRI on her hypothalamus during periods, before and after. Everything is ok. Did xrays on her ovaries also all ok. And still she continues to vommit so much, every 30 minutes during 12 hours on the first day of the periods. Every month we end up in ER. PLEASE HELP.