What Causes Vomiting And Stomach Pain Every Morning?

I have a 5 year old girl who is throwing up EVERY morning first thing when she gets up. She complains that she feels sick and needs to throw up. She then says that her stomach hurts. It is upper tummy area not lower. She will cry and kick her feet and moan. The pain comes and goes, it is not constant. Sometimes the pain lasts 20 or so minutes but has lasted over an hour before. Sometimes this happens after she eats, not every time after she eats. She also says that her throat burns and then she knows she has to go and throw up. She does not run a temp has had no injuries, if otherwise a very healthy kid. She drinks alot when she eats, always has and when she was little (like 2) I took her to the doctor because it seems like she could not swallow very well. She would spit out her food alot and need to drink before she could continue on eating.