Dr. Contreras received a BA in Biology from the University of Texas at Austin in 1984 and went on to graduate from the University of Texas Health Science Center in San Antonio in 1988.  Dr. Contreras completed his medical training with an Internal Medicine internship and residency and Gastroenterology fellowship at the University of Texas Health Science Center in Dallas, Texas from 1988-1994.

He was board certified for Internal Medicine in 1991 and Gastroenterology in 1995.

Dr. Contreras is a member of the McLennan County Medical Society, American College of Gastroenterology and American Gastroenterology Association.  He maintains privileges at Hillcrest Baptist Medical Center, Providence Health Center, and Waco Gastroenterology Endoscopy Center in Waco, Texas.