I have a stomach issue and have had it for years, it feels like indigestion and then i vomit brutally, and then diarrhea and it hurts so bad, i usually end up in the hospital and nobody can find out what is wrong, they checked everything?

A stomach specialist (Gastroenterologist) is needed in cases like this. Such symptoms can be a plumbing and/or motility issue. Motility means the muscle coordination in the gut, such that stuff moves smoothly and only in one direction, like a good highway. Plumbing is the way the gut was built, from before birth, and whether abnormal twists/turns/blockages exist. Special tests can check plumbing.