Hi, I get upper abdominal pain occasionally (maybe every couple of months?) and it lasts for 2-4 days at a time. It is right at the bottom of my ribcage, pretty much in the center. It only bothers me when I m standing or walking, to the point that I start feeling miserable or even nauseous. However, as soon as I sit down it pretty much goes away instantly. I also seem to feel like I need to belch more when this happens. I have tried everything, antacids, gas-x, pepto, pain relievers, nothing helps, it just has to go away on it s own after a couple days. I have gone to my local clinic after symptoms stopped and was seen by the RN, but nothing was done since the pain had stopped. What could this be??