Well, that is annoying--- I'm sure uncomfortable too. If you can't release the gas do you get a lot of pain? Have you looked into lactose intolerance? It can complicate this problem, so would cut down on your dairy.
You can try yoga. Don't laugh. But it can help force you to pass gas. Asanas (heard of the child's pose) and other positions might help. Chewing gum, drinking carbonated soda can help (and remember, our body releases gas TWO ways, tooting and burping).
what does your doctor say about this issue?