Re: Why don't even gastroenterologists know the cause?
Feel free to rant all you need to!
In some people, the LES is very weak. It looks OK, but it doesn't tighten the way it should. No one knows why this occurs, but it is believed to be a neuromuscular problem.
Also in some people, the stomach just empties slowly, which also contributes to acid reflux.
I'm also thin, healthy diet, etc. My reflux started at age 24 and got bad at age 29. I tried medicines like omeprazole, they worked for a while. Eventually I wound up getting surgery to strengthen my LES, which has helped a lot.