I've experienced that myself. It comes with my GERD. They aren't super intense but I definitely get them. They feel like terrible cramps. If you had Gallstones you'd know, no questions asked. My grandmother had Gallstones and it was the most horrendous pain she's ever had. She was breaking out in an intense cold sweat and threw up quite profusely, as well as having the inability to go through the idea in normal activity.
Yes! I had it really bad when I wasn't on any GERD medication. I didn't have any symptoms for years and didn't take meds for years and then in 2011 I think it was when I could barely eat anything and had horrendous pain in my middle back it was so bad. Then once I started taking medication I felt better.