November of last year, I randomly couldn't eat/swallow correctly for a few days, and when I did eat it would make my stomach hurt. Those first 2-3 weeks following (which were the worst of this whole thing) I had a constant pain in my stomach that would not go away and I couldn't digest anything correctly. Somehow I never threw up, but I was hunched over the sink a few times. Because eating/drinking irritated my stomach so much, I lost weight and had to visit the emergency room for dehydration.
It was awful.
Those symptoms continued until February of this year, gradually getting better but VERY slowly. Only in mid-February did I start feeling somewhat better, but I wasn't totally out of the woods just yet. I had mild digestive issues (after going to the bathroom my stomach would feel funny/sensitive) up until the beginning of June, then I was pretty much back to normal. My stomach doesn't rumble like it used to do when I'm hungry anymore.
Never found out what it was, but I assumed it was IBS and I was just having a flare up or something. It could have been a bug, but I was sick similarly in 2011 from July-November which makes me think IBS. So I know what you're going through and it's the absolute pits.
I was diagnosed with IBS but I don't know if it's combined with something else worse or what because I just don't think its normal to be in THAT much pain. 