John R. Hyatt, M.D.John R. Hyatt Jr., M.D., gastroenterologist, Baylor Medical Center at Garland and Baylor Regional Medical Center at Plano, Texas. Latest Articles by John R. Hyatt, M.D.Digestive HealthAre You Constipated?Changes in the frequency of your bowel movements, as well as other symptoms, may mean you’re constipated.