Nanticoke Rehabilitation Services

Ronald Concha-Parra, MD, is Board Certified in Internal Medicine and graduated from the Universidad Nacional de San Marcos School of Medicine in Lima, Peru. He completed his Internal Medicine residency at the University of Miami/Jackson Memorial Hospital, Miami, Florida and his Gastroenterology and Hepatology Fellowship at the State University of New York Downstate Medical Center in Brooklyn. Dr. Concha-Parra has been working as an attending gastroenterologist at Mercy Philadelphia Hospital since 2014. He was previously an attending gastroenterologist with TidalHealth Nanticoke from 2009 to 2014. His professional memberships include the American College of Gastroenterology, American Gastroenterological Association, and American Society for Gastrointestinal Endoscopy. Learn more about gastroenterology services

Bradley Mackler, MD, provides care at TidalHealth Gastroenterology in Seaford, Delaware. Dr. Mackler is board-certified by the American Board of Internal Medicine in gastroenterology. He is a member of the American Gastroenterology Association, the American College of Gastroenterology, the American College of Physicians and the American Medical Association.

Ismet Lukolic, MD, is board-certified in internal medicine, gastroenterology, and obesity medicine. He earned his Doctor of Medicine from St. George’s University School of Medicine in Grenada, West Indies. Dr. Lukolic completed his internship, residency, chief residency, and fellowship in gastroenterology at the State University of New York, Downstate Medical Center in Brooklyn, N.Y. His professional memberships include the American Medical Association, the American College of Physicians, the American Gastroenterological Association, and the American College of Gastroenterology. Dr. Lukolic is passionate about graduate medical education and patient safety. He serves as the associate program director of the TidalHealth Gastroenterology Fellowship and enjoys teaching medical residents. He is also dedicated to serving veterans of the U.S. Armed Forces and is an active volunteer for the Albanian-American Law Enforcement Association and the Law Enforcement Medal of Honor Committee. In his spare time, Dr. Lukolic enjoys traveling and outdoor activities.