I lived in Kansas City when I had my J-pouch surgery, but I flew to Los Angeles for the surgery. I was happy with my gastroenterologist in KC, though. That was almost 20 years ago.
If you can’t get a good referral from your primary care doc then you could start with the university hospital’s digestive diseases department. They *might* have somebody on the team with a strong background in J-pouches. I’d suggest starting with a gastroenterologist, and only moving on to a colo-rectal surgeon if it turns out that there’s a structural problem with your pouch.