My Son Has Been Experiencing Painful Upper Stomach Aches, Vomiting

my son has been experiencing painful upper stomach aches, vomiting and nausea at night. took him to emergency room, has been in the hospital for a week with high liver enzymes and two weeks later high ck levels. GI specialist has no idea what could be wrong. in fact no one does. his enzymes are back to normal now but last week was again at the ER with severe abdominal pain and vomiting.