Meet the Physicians

Our team of Board Certified Gastroenterologists diagnose and treat a full range of gastroenterological conditions.


Raj Mariwalla, M.D. – Dr. Mariwalla completed his residency at Jersey City Medical Center in Jersey City, NJ. He completed a fellowship in gastroenterology at State University of New York (SUNY), Stony Brook. Dr. Mariwalla is board certified in internal medicine and gastroenterology. He is a member of the American Society for Gastrointestinal Endoscopy (ASGE). Dr. Mariwalla maintains hospital privileges at Good Samaritan Hospital and Northwell Health’s Southside Hospital.

Darius Sorbi, M.D. – Dr. Sorbi completed his residency at State University of New York (SUNY), Stony Brook. He then went on to complete his gastroenterology fellowship at the Mayo Clinic in Rochester, MN. Dr. Sorbi is board certified in internal medicine and gastroenterology. He is a member of the American Society for Gastrointestinal Endoscopy (ASGE). Dr. Sorbi maintains hospital privileges at Good Samaritan Hospital and Northwell Health’s Southside Hospital.

William DiSanti, M.D. – Dr. DiSanti completed his residency and gastroenterology fellowship at Lenox Hill Hospital in New York, NY. He is board certified in internal medicine and gastroenterology. Dr. DiSanti is a member of the American College of Gastroenterology and American Gastroenterological Association. Dr. DiSanti has privileges at Good Samaritan Hospital and Northwell Health’s Southside Hospital.

Nabras Ahmed, DO – Dr. Ahmed graduated from the New York College of Osteopathic Medicine located in Old Westbury, NY. He then completed his residency in internal medicine at Largo Medical Center located in Largo, FL. He then went on to complete his fellowship training in gastroenterology at Kent County Memorial Hospital located in Warwick, RI. Dr. Ahmed is a member of the American College of Gastroenterology and the American Gastroenterological Association. Dr. Ahmed is board certified in internal medicine and gastroenterology.

Deepshikha Chowdhury, MD – Dr. Chowdhury completed her Internal Medicine residency from Mount Sinai School of Medicine – St. Joseph’s University Hospital, NJ , at the end of which she was elected Chief Resident. Subsequently, she completed a Gastroenterology and Hepatology fellowship from New York Medical College at St. Joseph’s University Hospital, NJ. She has a special interest in colorectal cancer screening, gastrointestinal cancers, biliary disease and inflammatory bowel disease. She is also trained and certified to perform ERCPs ( Endoscopic Retrograde Cholangiopancreatography).

Fluent in English, Bengali and Urdu/Hindi, Dr. Chowdhury has authored several publications on varied topics in many peer-reviewed journals and is an active member of the American College of Gastroenterology, American Gastroenterological Association and the American Society of Gastrointestinal Endoscopy. She is board certified in Internal Medicine and Gastroenterology.