If you are looking for east valley I would agree that Dr. Shapiro would be highly recommended as well as Dr. Leighton (if you can get an appt with him). I've been treated at Mayo clinic for surgery, but only when no one in my insurance network would do it.
I have also been a patient of Dr. Bruce Sand, who is near Desert Ridge Mall. He was my Dr for many years until my case became too complicated for his expertise. He referred me to Dr. Nizar Ramzan in Scottsdale and he was excellent. If we lived in that area he would still be my Dr., very thorough and spent time explaining everything clearly. He is a former Mayo clinic Dr.
I now see a GI dr. in Surprise, AZ - Dr. Lawrence Bettinger...
Hope you find someone to help. There are some very good Dr's out there, sometimes just hard to find the right one for you.