Suggest Treatment For Back Ache

My 12 year old granddaughter is having back ache just at below the shoulder blade to right of spine. It hurts to put her chin down on chest and depending on movement pain shoots down arm, down back or up neck. Her parents have been taking her for chiropractor treatments and he is saying he feels movement in one rib which he thinks is out of place but won t stay in place. He took X-rays and keeps commenting on how much gas he sees and can t believe she diesnt have gas pains. Her mom asked if he s sure it s gas and could it be something else but he said its diffiantly gas. My question...isn t it unusual for a 12 year old to have a problem with gas and can you see gas on an X-ray? Could it be mistaken for something else on the X-ray or is it easy to tell if it s gas. This has been going on for over a month now and treatments don t seem to help and I think the problem is getting worse not better. Any advise?