Sorry guys your all wrong, its not trapped wind in the shoulder, i know cause i had it and i found out exactly what it is !
The pain your experiencing in your left shoulder is a by product of laproscopic surgery, they are not sure what causes it, but lots of people that undergoing laproscopic surgery whether WLS or any other experience the pain in the back or front of their left shoulder.
The good news is it eventually will fade and go of its own accord, the bad news though in me it took about 2 months !
There's nothing they can do about it (i was told) but i found sitting with a heat pad on my shoulder helped !