My Daughter Is A Year And A Half. She Drinks

My daughter is a year and a half. She drinks whole milk daily with no problem. Laid her down for the night with no problem and then woke up around 1 crying. She fell off the couch earlier and thought she might of had a headache. (I have two kids, I really don't think it was a hard enough fall for a concussion) I went to give her Motrin and she instantly grew up huge chunks of milk. It smelled terrible and just kept coming. Her body just kept dry hieving. Could it be just a stomach bug? No fever, no sickness.