Hi I have been having gas pressure in upper and middle back. a little resting it moves and i feel better. it returns in a few days the sympthoms return pressure in lower and upper back. what can be causing this? my diet consists of vegatables, chicken, fish, tea, sometimes pastries,eggs,milk. I am a 54 year old very active male. excercise a couple days a week don 't drink or smoke. Any answers will help