It started with blood in my stool, through nausea and now vomiting and no appetite. i've had a colonoscopy, egd and ultrasound without results.stress?

It could be...: You are too young to have any of the serious ailments for which we would ordinarily do egd and colonoscopy etc. Why do not you try to do a couple of simple stress reduction activities like a daily walk for 30 minutes and some meditation or yoga or even simple breathing exercises as means of stress reduction and see if it would all settle down.