Hi Kevin, You may have already heard of and/or tried this, but I thought it wouldn't hurt to share, maybe it might help some others out there too.
I also experienced stomach discomfort off and on for many years. Two things really seem to have helped more than anything. First, in 2011, for lent I decided to fast completely (water only) from each Thursday night until Saturday morning, I was also praying and attending adoration every Friday evening too. Well I am sure God's grace played a role, but I can't help but think that the fasting did something to me physically - I just felt a lot better.
And then the second thing I did, which really made my stomach problems vanish - I did one of those over the counter cleanses that takes about two weeks, and then I took raw probiotics for men; I have felt fine ever since. I can eat anything again, and if I want to be daring (or stupid depending on your definition) and eat tons of super spicy food, I just take one or two of those probiotic pills and I feel perfectly fine.
I don't sell probiotics or anything like that, I am just sharing something that I wish I learned ages ago...