Dr. Wallen C.Y. Chan and the office staff are dedicated to providing the highest level of care to all patients. Dr. Chan earned his Medical Doctorate at the Mount Sinai School of Medicine in New York. He then completed his Internal Medicine residency training at the Mount Sinai Hospital in New York. Dr. Chan then completed his Gastroenterology fellowship at the Medical College of Pennsylvania, in Philadelphia. He is board certified by the American Board of Internal Medicine in both Internal Medicine and Gastroenterology. He has been in private practice since 1994 and sees patients in both Staten Island and Brooklyn. He is currently affiliated with Richmond University Medical Center as well as Maimonides Medical Center. Dr. Chan is a Fellow member of the American College of Gastroenterology (FACG). He also holds memberships in the American Gastroenterological Association (AGA), the American Society for Gastrointestinal Endoscopy (ASGE), and the New York Society for Gastrointestinal Endoscopy (NYSGE).

Dr. Daoud received her undergraduate degree in biology, and her graduate degree of medicine and surgery and post graduate master’s degree of science in internal medicine from the University of Ain-Shams in Cairo, Egypt. After completing her education, Dr. Daoud went on to complete her residency in internal medicine at Hofstra University School of Medicine at Staten Island University Hospital, where she served as the chief medical resident. She then went on to complete a fellowship in gastroenterology at Staten Island University Hospital. Dr. Daoud is fluent in English and Arabic and has published a number of research papers on gastroenterology.

Dr. Richard A. Fazio has been in private practice for over 40 years, with offices in both Staten Island and Brooklyn. His philosophy is to achieve and maintain the highest standards of practice in order to best manage his patients’ care with the latest treatment modalities. He is a clinical professor of medicine at SUNY Downstate and an assistant clinical professor of medicine at New York Medical college. He is a Fellow member of the American College of Physicians (FACP), the American College of Gastroenterology (FACG) and the New York Society for Gastrointestinal Endoscopy (NYSGEF). He also holds memberships in the American Gastroenterological Association (AGA), the American Society for Gastrointestinal Endoscopy (ASGE), the American Association for the Study of Liver Diseases (AASLD), the American Medical Society (AMA) and the Richmond County Medical Society.

Dr. Fazio earned his Medical Doctorate degree from the University Di Bologna in Bologna, Italy. He then went on to complete his Internal Medicine residency at Maimonides Medical Center in Brooklyn, New York. Dr. Fazio then completed his Gastroenterology fellowship at Saint Vincent Medical Center (Richmond University Medical Center) in Staten Island, New York. He has authored many publications, including some of the original case series on Candidal Esophagitis. He is consistently named a “Top Doctor” by Castle Connolly and a “Best Doctor” by New York Magazine. He is board certified by the American Board of Internal Medicine in both Internal Medicine and Gastroenterology. He is affiliated with Richmond University Medical Center and Maimonides Medical Center.

Dr. Roberts received his undergraduate degree from New York University and went on to receive his MD from St. George’s University. He completed an internship in internal medicine at SUNY Downstate Hospital and his residency in internal medicine at Long Island Jewish Medical Center Albert Einstein. Dr. Roberts also completed a chief residency in internal medicine at Nassau County Medical Center at Stony Brook and then went on to complete a fellowship in gastroenterology at Long Island Jewish Medical Center Albert Einstein.

Dr. Vahe S. Shahnazarian is the latest physician to join our practice. He earned his Masters in Public Health degree at the California State University, Northridge and his Medical Doctorate from Ross University School of Medicine. He then completed his Internal Medicine residency at New York Presbyterian Brooklyn Methodist Hospital. Dr. Shahnazarian served as a Chief Administrative Medical Resident at New York Medical College (Metropolitan) and completed his Gastroenterology fellowship at the Brooklyn Hospital Center, a clinical affiliate of the Mount Sinai School of Medicine. Dr. Shahnazarian is a Clinical Instructor of Medicine at New York Medical College. He is also a Fellow member of the American College of Physicians (FACP), and a member of the American Gastroenterological Association (AGA), the American Society for Gastrointestinal Endoscopy (ASGE), the American Association for the Study of Liver Diseases (AASLD), the American College of Gastroenterology and the New York Society for Gastrointestinal Endoscopy (NYSGE).

Dr. Shahnazarian is board certified by the American Board of Internal Medicine in Gastroenterology and Internal Medicine. He has numerous publications in renowned journals, as well as many presentations at the national Gastroenterology conferences, which he regularly attends. He has been named a “Best Doctor” by New York Magazine. Dr. Shahnazarian sees patients in both our Staten Island and Brooklyn locations, and he is affiliated with the Richmond University Medical Center, Staten Island University Hospital and Maimonides Medical Center. He brings his tireless dedication, work ethic and modern/cutting edge approaches to the practice. Dr. Shahnazarian employs an evidence based methodology and includes his patients in the decision making process in order to provide the best, safest and most satisfactory outcomes as possible.

Dr. Vaizman has been a board certified gastroenterologist since 2011. He completed his undergraduate degree at Brooklyn College and went on to complete his medical education at St. George’s University School of Medicine in Grenada, West Indies. Dr. Vaizman completed an internal medicine residency at Maimonides Medical Center in Brooklyn and served as a clinical fellow in the department of transplant hepatology in at Mount Sinai Medical Center. Dr. Vaizman is fluent in Russian.

Dr. Xu completed his medical degree in 1986, and then became a lecturer in microbiology at the Yanbian Medical College, China. In 1991, he moved to the US and started to work as a research scientist in the virology department at the NYS Institute for Basic Research on Staten Island. In 2007, following residency and chief residency in pediatrics at the St. Vincent Medical Center, he joined a fellowship in pediatric gastroenterology, hepatology, and nutrition at SUNY Downstate Medical Center at Brooklyn, where he became full-time faculty as an assistant professor.

In 2017, he returned to RUMC and became program director of the residency program and chief of gastroenterology in the department of pediatrics. His research portfolio and interest include both basic science (molecular biology and gut immunology) and clinical gastrointestinal disorders (inflammatory bowel disease, necrotizing enterocolitis, hepatitis B, parenteral nutrition-associated liver disease and nonalcoholic fatty liver disease).