Our Physicians

The physicians and staff at Islandwide Gastroenterology are dedicated to serving your digestive health care needs.

Dr. Philip Cassar

Dr. Philip Cassar has been in private practice for over ten years. He is the founder and president of Islandwide Gastroenterology in Garden City, NY. He is currently the Chief of Gastroenterology at Mercy Medical Center. He completed his Gastroenterology fellowship at Winthrop University Hospital and is currently Board Certified. He is a former Chief Medical Resident of Winthrop University Hospital. He is a member of the American College of Gastroenterology. He specializes in Endoscopy, Colonoscopy and performs all the advance procedures for the practice that includes Endoscopic Retrograde Cholangio-Pancreatography ( ERCP), Esophageal and colonic dilation of strictures and the placement of endoscopic stents. He is certified in the placement and removal of the Orbera Intra-Gastric Balloon for weight loss.

Dr. Eleazer Yousefzadeh

Dr. Eleazer Yousefzadeh received his medical degree from the Albert Einstein College of Medicine. He completed residency at Montefiore Medical Center where he was awarded the Outstanding House Officer Award.  His gastroenterology fellowship training was performed at University of Medicine & Dentistry of New Jersey. Dr. Yousefzadeh is board-certified in both Gastroenterology and Internal Medicine. He was appointed Clinical Assistant Professor of Medicine at Drexel University College of Medicine before joining Islandwide Gastroenterology. He is a member of the American College of Gastroenterology. He treats all gastrointestinal and liver diseases. He has a special interest in the management of Inflammatory Bowel Disease, a focus of his clinical practice.

Dr. Robert Bonasera

Dr Bonasera is a graduate of St. George’s University School of Medicine. He is board-certified in internal medicine as well as gastroenterology. His medical training was completed at Winthrop University Hospital, where he served as chief medical resident.

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