I love my GI and he's in Grand Rapids, MI: Dr. Benny Kieff. The problem is that he is so good that I'm not sure he's taking new patients. I've heard a lot of the other doctors with him are good too, but I don't have personal experience with any of them.
Look up Spectrum Health Medical Group Gastroenterology. They are on E. Paris Ave. in G.R. very easy to get too!