Excruciating stomach pains...?

I get stomach aches that hit me all the sudden. The pain fluctuates. It gets unbearably bad, to the point where you can't sit still and feel like crawling out of your skin. A minute later it will subdue, just to arise again. I've kept track of what I'm eating and there doesn't seem to be a correlation between what I eat. I think food triggers it and makes it worse, but it's not every time I eat. Episodes are short, anywhere from 5- 30 minutes. I've tried everything, ibuprofen, tums. Nothing helps. Any ideas on what this could be?