Meet the GI Physician Team
William M. Tierney, MD, FASGE
Professor of Medicine
Director of Endoscopic Ultrasonography
Dr. Tierney received his medical degree from Yale University in 1990 and subsequently completed a residency in Internal Medicine at the University of Pennsylvania. He also completed a fellowship in Gastroenterology at the University of Michigan where he received 2 years of dedicated training for EUS and ERCP. He is currently Professor of Medicine at the University of Oklahoma and serves as Director of Endoscopic Ultrasound, Vice Chief of the Section of Gastroenterology, and Director of the Gastroenterology Fellowship Program. He is board certified in Internal Medicine and Gastroenterology and has pioneered several endoscopic procedures in the state of Oklahoma.
John T. Maple, DO
Assistant Professor of Medicine
Director of Interventional Endoscopy
Dr. Maple was recruited to OU Medical Center in 2007 as an Assistant Professor of Medicine, and was named Director of Interventional Endoscopy in 2008. A native Oklahoman, he attended Oklahoma Christian University and graduated from Oklahoma State University - College of Osteopathic Medicine in 2000. Subsequently, he completed an Internal Medicine residency and Gastroenterology fellowship at Mayo Clinic College of Medicine in Rochester, Minnesota. Dr. Maple then completed an Advanced Endoscopy fellowship at Washington University in St. Louis, focusing on training and clinical research in ERCP and EUS. He is board certified in Internal Medicine and Gastroenterology and has pioneered several endoscopic procedures in the state of Oklahoma.
Tauseef Ali, M.D.
Dr. Ali is a fellowship-trained gastroenterologist. He is an assistant professor of research at the OU College of Medicine. Ali is board certified in internal medicine. He has a specific experience in diagnosing and treating patients with inflammatory bowel diseases including Crohn's disease and ulcerative colitis as well as acid reflux disease. Ali recently completed a gastroenterology fellowship at the University of Oklahoma College of Medicine, where he also completed an internal medicine residency and internship. During his fellowship, he also went to the University of Chicago to gain extra training in Crohn's disease and ulcerative colitis. Prior to coming to Oklahoma, he served as medical officer at a cancer research institute in Pakistan. He earned his medical degree from King Edward Medical College, Lahore, Pakistan. Ali is an active member of the American College of Physicians, American College of Gastroenterology, Amercian Gastroenterology Association and Crohn's and Colitis Foundation of America. He is also serving on the International Relations Committee of the American College of Gastroenterology and the Continuing Medical Education Advisory Board of Southern Medical Journal.
Gary D. Dunn, M.D.
Dr. Dunn is a native of Oklahoma City, and an associate professor with the University of Oklahoma College of Medicine. Dunn is board-certified in both colon and rectal surgery and general surgery. He specializes in the surgical management of colon and rectal cancer, inflammatory bowel disease and complex anorectal-pelvic floor disease. This includes a new surgical technique he brings to Oklahoman, called Transanal Endoscopic Microsurgery, a minimally invasive treatment of rectal neoplasms (abnormal growth of tissue). Dunn comes to OU Physicians from Louisiana State University Health Sciences Center (LSUHSC), Shreveport, where he a clinical Associate Professor of Surgery and Associate Program Director of Colon and Rectal Surgery. He earned his medical degree from New York Medical College and earned his undergraduate degree from Oklahoma State University. Dunn is a fellow of the American Society of Colon and Rectal Surgery and the American College of Surgeons. He served in the U.S. Army Reserve Medical Corps, retiring in 2005.
Javid Fazili, M.D.
Dr Frzili is a board-certified gastroenterologist and Associate Professor at the OU College of Medicine. He has a special interest in hepatology and liver transplantation. Fazili completed a fellowship at Albert Einstein Medical Center, Thomas Jefferson University Hospital. He completed a residency at the University Institute of Medical Sciences, Nassau County Medical Center and earned his medical degree from the University of Kashmir.
Ralph T. Guild, III, M.D.
Dr. Guild is a board-certified gastroenterologist and a professor at the OU College of Medicine. He sees patients at the VA. He has a special interest in diagnosing and treating patients with Gastroesophageal Reflux Disease and Peptic Ulcer Disease. Guild completed a fellowship and residency at the University of Florida after earning his medical degree at the OU College of Medicine.
Sam Hong, MD, MSCI
Assistant Professor of Medicine
Dr. Hong joined the gastroenterology faculty at OU Medical Center in 2011. After first receiving a BS in Biochemistry from the University of Michigan, Dr. Hong completed his medical school training at Vanderbilt University in 2003. He then completed an Internal Medicine residency at Washington University in St. Louis, and subsequently returned to Vanderbilt to train in Gastroenterology. While completing his Gastroenterology fellowship, Dr. Hong also obtained a Masters of Science in Clinical Investigation. He subsequently completed an Advanced Endoscopy fellowship at Thomas Jefferson University Hospital in Philadelphia, with additional focused training in ERCP and EUS. He is board certified in Internal Medicine and Gastroenterology and brings another resource of expertise to the state of Oklahoma.
Courtney W. Houchen, M.D.
Dr. Houchen is section chief of digestive diseases, Department of Medicine, at the University of Oklahoma College of Medicine. He also holds the Frances & Malcolm Robinson Chair and is an associate professor. Houchen is board-certified in internal medicine and board-eligible in gastroenterology. He has a specific interest in preventing, diagnosing and treating gastrointestinal cancers, colorectal cancer screening, prostaglandin receptor and gastrointestinal injury. He comes to OU Physicians from Washington University School of Medicine, St. Louis, where he completed a gastroenterology fellowship. He completed his residency at the University of Maryland Medical Center, College Park, and earned his medical degree at Temple University School of Medicine, Philadelphia.
Donald J. Kastens, M.D.
Dr. Kastens is a board certified gastroenterologist and an Associate Professor at the OU College of Medicine. He has a special interest in diagnosing and treating patients with esophageal motility disorders and Gastroesophageal Reflux Disease. Kastens completed a fellowship, residency and earned his medical degree at the OU College of Medicine.
Philip B Miner Jr, MD
Dr. Miner is a board-certified gastroenterologist. He has a special interest in diagnosing and treating patients with inflammatory bowel disease, gastroesophageal reflux disease, fecal incontinence, functional gastrointestinal disease and esophageal motility disorders. He completed a fellowship at the University of Colorado and his residency at New York University. He earned his medical degree at the University of Colorado.
Jessica R. Philpott, MD, PhD.
Dr. Philpott is a fellowship-trained gastroenterologist and an assistant professor at the OU College of Medicine.
Philpott is board certified in internal medicine and board eligible in gastroenterology. She has specific interest in diagnosing and treating patients with inflammatory bowel diseases including Crohn's disease and ulcerative colitis as well as women's gastrointestinal health issues and transitional care from pediatrics. Philpott completed a fellowship in gastroenterology and hepatology at the University of Oklahoma College of Medicine. She completed her internal medicine residency, earned her medical degree and doctorate in medical microbiology at The Ohio State University College of Medicine and Public Health, Columbus.
David Neil Roberts, M.D.
Dr. Roberts is a fellowship-trained gastroenterologist and an assistant professor for the OU College of Medicine. He has a specific interest in capsule endoscopy and hepatology. Roberts is board certified in internal medicine and board eligible in gastroenterology. He completed a gastroenterology/hepatology fellowship at the University of Oklahoma College of Medicine, where he also earned his medical degree. He completed an internal medicine residency at the University of Alabama at Birmingham and graduated summa cum laude with a bachelor of science degree in biology from Oklahoma Christian University. Roberts is a member of the American Association for the Study of Liver Diseases, the American College of Gastroenterology, the American Gastroenterological Association, American Society for Gastrointestinal Endoscopy and the American College of Physicians.