This just recently started happening with me:
For a while I was getting a little less fiber, and over about 6 weeks of it, started developing a pain/pressure in my left side, right under my lowest rib. It wasn't major, just and on and off thing, but annoying. This was paired with major acid reflux, which would come and go, and be quite intense at times. I'd take some antacids and it'd get better, but kept coming back. I noticed other restroom related signs of low fiber as well, which I won't go into, but you can probably imagine.
Fast forward to this week, and I got some Bob's Red Mill Gluten Free Oats, after one day of eating them, there's been a massive drop in the above symptoms, which means my fiber guess was probably what was behind it all.
My question for you guys, is has anyone encountered something similar? I know fiber is a HUGE issue for all of us so I'm guessing I'm not alone in that part at least, but what about the pain in the side/acid reflux? I guess I'm just wondering if this is all in my head, or if I'm not alone in it.