What Causes Vomiting, Fever, Stomach Cramps And Pain With Back Pain?

My 9 year old daughter has been throwing up gray vomit off and on for about 2 days. She is running a fever anywhere from 99.9-101.5 so its not to terribly high. She keeps complaining of stomach cramps and back pain. When I ask where the pain is in her stomach she says right in the middle by her belly button but then says that the right side of her back is the part that hurts? Is this something I should seek medical attention for?