Suggest Treatment For Rashes All Over With Diarrhea And Vomiting

My daughter has browken out in a rash or what I think is a rash. Her skin is bright pink on her back and back of her neck mostly, a little on her chest and stomach. She has thrown up twice and has a little bit of diahera (I know I didn't spell that right). The vomit and bowels smell like rotten egg. She's been sick like this before, but the rash is new. I am wondering what it might be.