Brennan Spiegel, MD, MSHS is an Associate Professor of Medicine in the Division of Digestive Diseases, UCLA School of Medicine, and in the Division of Gastroenterology, VA Greater Los Angeles Health Care System. He also serves as adjunct faculty in the UCLA School of Public Health, where he teaches health services research techniques. Dr. Spiegel served as the Program Director for the UCLA GI Fellowship Program, where he developed and expanded the lecture series that gave rise to the series of Acing books.

Hetal A. Karsan, MD, FACG, FACP is a Clinical Associate Professor of Medicine in the Division of Digestive Diseases at Emory University School of Medicine in Atlanta. He is a gastroenterologist and hepatologist at Atlanta Gastroenterology Associates, one of the largest gastroenterology groups in the country, at which he is a partner. He is also a practicing clinician at Emory University.