Could be.  Just keep pressing the morphine pump and walk, a lot.  Good luck, it will get better. 

Gas pain post-op is the worst.  Try to get up and move around as much as possible.  The threat of the dreaded NG tube my scare your bowel into moving some of that gas out.

You might try various positions to place your J-pouch higher than your stomach.  Getting down on all fours with your buttocks elevated may help the gas rise and exit.  Another position/activity which has helped me is to sit on the toilet and cough hard several times.  The gas comes exploding out of me!  I've also stood in the shower and held the shower wand in my hand while letting the hot/warm water spray shoot straight up "you know where".  This has seemed to relax the sphincters so that the gas can more easily exit my body.  It's a bit of a mess but it is easy to clean because you are in the shower!  Best wishes.

CeeeeCeeee, when I'm backed up, a warm Sitz bath does the same thing: relaxes things, then, blammo! Out it comes.