Dr. John Tung graduated from Guy's Hospital Medical School in London in 1988, and worked in different hospitals in London including the Hospital for Sick Children, Great Ormond Street, before coming to the United States to complete his pediatric residency at University of Vermont. He did his fellowships in pediatric gastroenterology at Children's Hospitals of Philadelphia (CHOP) and Advanced hepatology and liver transplantation in Kings College Hospital in London and completed Specialty Certification in England (CSST). He was attending pediatric gastroenterologist and director of liver transplantation at Nemours Children's Hospital before moving to private practice in South Jersey. He established South Jersey Pediatric Gastroenterology in Mays Landing in Voorhees for 20 years before joining Advocare.