I've had stomach issues for a bit too. Probably not anything like you have had to deal with, but I often wonder if some of it is in my head. I think anxiety plays a part in it for sure and I often make it worse than it needs to be anticipating that it is going to be bad. I also think there are a lot of things I have missed out on because I didn't want to be in a position where my stomach problems would be an issue.
I think a lot of it is, or at least, the head makes it much worse. I had issues for so long that I was able to run experiments for many different things. One thing that does help though that isn't head related, is cutting down carbs significantly for a couple months, then slowly introducing again, but keeping them pretty low still.
This I understand a lot. I feel I missed my university years and much of my mid twenties because of it. It has only been in the last ten years I have been freer to move again, though it is still always on my mind, somewhere at the back there.
That's very interesting as I have often wondered if excessive carbs was at the root of my issues. I've never really talked to the doctor about it. I've also noticed that as well have increased my water intake I seem to have less issues. Either that or it has just went away as I have gotten older.
It is an easy start to explore. If you are interested, there is a great book that explains why:
https://www.amazon.com/Life-Without-Bread-Low-Carbohydrate-Diet/dp/0658001701
Thanks! I'll definitely check that out!