What is this pain I've been feeling?

I have been a vegetarian for a little over a year, but a few months before I began this lifestyle I developed something I referred to as the 'tummy feeling'. This was a gy uncomfort in my lower abdomen that seemed to come right out of no where. My doctor said it could possibly be lactose intolerance, and to test it out by not eating any and then seeing how I feel after a gl of milk. I'm pretty sure that was the case, so now I avoid dairy products and/or use the aid of dairy dietary supplements. The past few weeks though, I've been feeling gy and achy even if I havent had anything to eat, or if I've made certain not to have anything with dairy. I used to think I had IBS, and as of lately I've started to think that might be accurate. Also I get sharp aches within 10 minutes of eating. Any ideas?