Dr. Hallett received his graduate degree from the University of Illinois in 1987, and has
completed his internal medicine residency at Barnes Hospital, Washington University
and fellowship in gastroenterology at Barnes Hospital, Washington University. He has
been with Digestive Care Center since December 2019.
He is certified by the American Board of Internal Medicine and the American Board of
Internal Medicine – Gastroenterology. In addition to providing consultative
gastroenterology care, he specializes in upper endoscopy, colonoscopy, therapeutic
endoscopy (ERCP), and motility disorders of the esophagus and colon.
Dr. Hallett is a member of American Gastroenterological Association (AGA), and the
American Society for Gastrointestinal Endoscopy (ASGE). He is the Friends of Tenwek
Gastroenterology/Endoscopy Champion, and he leads the Surgical Endoscopy Task
Force for the Pan-African Association of Christian Surgeons.
Dr. Potteiger received his graduate degree from Philadelphia College of Osteopathic
Medicine in 1998, and has completed his internal medicine residency at Geisinger
Medical Center. He was Chief Medical Resident for internal medicine at Geisinger
Medical Center. Dr. Potteiger has completed his fellowship in gastroenterology and
nutrition at Geisinger Medical Center. He has been with Digestive Care Center since
He is certified by the American Board of Internal Medicine – Gastroenterology. In
addition to providing consultative gastroenterology care, he specializes in colonoscopy,
upper endoscopy and nutrition/weight management.
Dr. Potteiger is involved in many professional societies include: American College of
Gastroenterology, American College of Physicians and American Society for
Dr. Zara was born in New York City. He received his medical doctorate at the Albert Einstein College of Medicine in the Bronx, New York. He completed his Internal Medicine Internship/Residency, and his Gastroenterology Fellowship at the University of Miami. He is Board Certified in Internal Medicine and Gastroenterology. He is a Fellow of the American College of Internal Medicine and Gastroenterology. Dr. Zara is a highly experienced gastroenterologist with years of training and responsibility. He is skilled in the full spectrum of GI and liver disease, as well as therapeutic and interventional endoscopy. As a GI hospitalist for DCC, Dr. Zara’s main focus will be to evaluate and treat hospitalized patients with GI issues. In his spare time Dr. Zara enjoys playing tennis and basketball, following the major sports, watching movies and traveling.