Hiatal hernia? More likely probably, reflux disease can feel like that, too (often referred to as GERD). I agree this doesn't sound pouch related. I had "fullness" feelings for a time, coupled with some nausea, and what helped was using the med called Prevacid (even though it's over the counter, I talked with my doctor), and it helped. Twice I've gone on a fourteen day treatment, and it helped, but modifying my meals, and eating smaller meals, really helped long term, and while I occasionally take a Pepcid here or there, I'm off the Prevacid. A med like Prevacid needs taken more than here or there, you need consistent days with it, though, so one pill won't work; with Pepcid, you can take it sporadically for symptoms.
But really, you need to talk more to your MD.