Dr. Lenz received his medical degree from the University of Hamburg in Germany and completed residencies in internal medicine at the University of Hamburg and University of California, San Diego School of Medicine. He then earned a postdoctoral fellowship in neuroscience from the Salk Institute in La Jolla, Calif., and received fellowships in gastroenterology from the University of Hamburg; University of Liverpool, England; and the University of California, San Diego. He is a member of the American College of Physicians, American Gastroenterological Association, American Association for the Study of Liver Disease, American Society of Gastrointestinal Endoscopy and the American College of Gastroenterology. He focuses on the diagnosis and treatment of all gastrointestinal and liver diseases with special interest in the esophagus (heartburn, reflux and swallowing disorders). Additionally, he has studied and now applies the knowledge of how the brain and stress affect the gut.