Yes, it could be something in my diet. I'm actually diabetic right now because of a medication I'm on, so I'm pretty limited in what I can eat, so eliminating foods is not easy for me. I suspect lactose, actually, since I am a bit intolerant, although I suppose it could be wheat or something else. I don't drink carbonated beverages ever, and eat baked potatoes and peppers pretty rarely. I suppose I could get rid of lactose - that is so tricky though because milk products are in everything. I will give it a try.
PS - Last night I did some acrobatic jiggling and got burps out each time. No wakings in between feedings, so that is good, although he still wakes every 2-3 hours to eat. That is so annoying. I thought by 3 months he would be doing better. Oh, well.