Hi there:
i have that issue as well - but i have confirmed gastroparesis. The gas is from the food sitting and "rotting" (sorry i know - gross) in my stomach. i have found that GasX helps some. for me though it is a "relief" to belch because if i don't the gas is trapped in my stomach and causes aching pain. Do you have another other GI conditions - like acid reflux etc - have you had an upper GI study??