John Coombes, M.D., is a graduate of the University of California, Davis and received his medical degree from Yale University School of Medicine. He completed his medical residency and Gastroenterology fellowship at the University of Colorado in Denver, CO. He joined GI Associates in 2006. Dr. Coombes areas of interest include colorectal cancer screening/prevention, celiac disease, and inflammatory bowel disease. Dr. Coombes maintains active board certification in gastroenterology and actively participates in maintenance of certification requirements. He is an active member in the American College of Gastroenterology, the American Gastroenterological Association and the American Society for Gastrointestinal Endoscopy.