I'm so focused on scopes these days, I've completely left out the other tests! There's upper and lower GI's which might be good ones for your issue (and much less invasive). A pocket could mean a diverticulum like I have and what that means is you need to watch certain foods so it doesn't get inflamed and turn into diverticulitis which is painful. They call it an "old persons disease" but supposebly I've had it since I was ten. I'm not so sure about that and think my doc back then may have been a quack (can't find the records from then anywhere).
Anyway, hannahw and CRguy have all given you good advice, go see a GI doc.