CXray was normal, Pulm Doc said there was some gas under diaphragm. I do get what seems to be gas pains which I'm treating. Can u see gas on CXray?

Yes. X-rays show anatomy and problems based on density. Bones are dense and show up white on X-ray. A metal object is even denser and can be seen if one is there. Gas is not dense and shows up as black areas, whether in the lungs, or under the diaphragm. Tissues of in-between density will be in-between in color.