Well, this is a first. Scared the crap out of me. I was ready to go to the hospital if the pain did not subside. Granted this was after eating a very plentiful Thanksgiving day dinner and pie ( Sorry Brits. Just realized you probably don't celebrate this holiday). I got a very sharp pain in my left rib cage where I was afraid to breathe deeply. I could shallow breathe slowly, but not deep breathe without excruciating pain. It went away after about 5 - 10 minutes. Very scary. I thought I was dying of a heart attack. Anyone ever experience this? If so, what is it? I looked up could be gas in the intestines causing this pain even though up in my rib cage. If anyone can share a similar experience, I would really appreciate.