Hold on....


Now, did your snake always have this condition? Like his appearence did he always look big in the one area of his body. Sounds kind of fishy thought I think. If he always looked like that then I bet you its "hard belly"

Hard Belly- This condition is thought to occur when babies are hatching they are pulled from the egg before they have ample time to absorb the yolk. Some of these babies fail to thrive, while others may live. The hardened yolk may create an obstruction that can not be digested an ultimately the snake starves. There is no cure for this problem.(all info from The Ball Python Manual by Kevin McCurley)

I just really doubt its a gas problem, but regardless it is what it is, and it sucks. I would honestly re-think where your bring your animals. Not saying hes a bad guy, but did he didn't mention this condition and went straight to diagnosing it with gas, sounds kind of like a premature diagnosis. Good luck, and hopefully he turns around.