Dr. McGreen received his undergraduate degree from Providence College and his medical degree from the Universidad Autonoma de Guadalajara School of Medicine and New York Medical College. He completed an Internal Medicine Residency at St. Vincent's Medical Center in Bridgeport, CT, an affiliate of Yale University and New York Medical College and a Gastroenterology Fellowship at The University of Illinois in Chicago.

Dr. McGreen is board certified in Internal Medicine and Gastroenterology. He is a member of The American College of Gastroenterology, The American Society of Gastrointestinal Endoscopy and The American Gastroenterological