Dr. Rettig completed her undergraduate work at Iowa State University in Ames, Iowa where she earned a Bachelor's degree in Psychology and a Master's degree in Biological Psychology and Neuroscience. She received her medical degree from the University of Minnesota and completed her internship and residency at Hennepin County Medical Center in Minneapolis. She joined MNGI Digestive Health (previously Minnesota Gastroenterology) in July 2004 after completing a three year fellowship in gastroenterology at the University of Illinois at Chicago. Dr. Rettig is a member of the American Society of Gastrointestinal Endoscopy, the American College of Gastroenterology, the American Gastroenterological Association and the Crohns and Colitis Foundation.