Dealt with very bad acid reflux and heartburn for about a decade until I got insurance (roughly 4 years ago). At that point we found a duodenal ulcer caused by h pylori bacteria. That was treated back in 2017, and I then began a long-term regiment of omeprazole. I was on that for a year, tried to get off, and no go. At this time I switched doctors as well because I was never all that happy about the first gastro.
The next gastro found that I had giardia, so we addressed that. After all said and done I probably collected about a dozen samples of stool and gave a pint away for all these tests over the last two-ish years.
Since then no more giardia despite all of the tests; however, each night there is a Civil War reenactment in my guts (no acid, no heartburn though), and I have since developed intolerances to caffeine, any form of coffee, lactose, some other dairy, chocolate, and a few other odds and ends. I am leaps and bounds better than I was a year ago, two years ago, and a million times better than four or five years ago when I'd randomly throw up acid (it was bad).
Anyways, we still know very little about what's going on in my gut, but with more tests coming we'll see...pretty much throwing darts at a wall, in the dark, blindfolded, from 20 feet away, hoping something sticks : )