My 17 year old son has had severe dry heaves on and off for over a week and is now vomiting orange, he is extremely fatigued, falling asleep when out with friends, he is experiencing green stools, back ache, neck ache, abdominal pain and burning when he urinates. He does not have a fever. Prior to this he had a headache for 2 weeks straight. His headache has stopped. What could be wrong? He continues to go to school keeps up his regular schedule despite all the dry heaving and nausea although very severe comes and goes.