Meet Our Physicians

The gastroenterology team at Mount Sinai South Nassau provides innovative and leading-edge endoscopic techniques to address a variety of gastrointestinal disorders.

Frank G. Gress, MD
Dr. Frank Gress is the Chief of the Division of Gastroenterology & Hepatology and Chief of Interventional Endoscopy at Mount Sinai South Nassau. He also serves as the lead for therapeutic endoscopy for Mount Sinai on Long Island, and holds an appointment as Professor of Medicine in the Division of Gastroenterology at the Icahn School of Medicine at Mount Sinai. Dr. Gress is board certified in Gastroenterology. He completed his medical degree from Mount Sinai School of Medicine in New York, NY. Dr. Gress completed residency training in Internal Medicine at Montefiore Medical Center in New York, NY. He completed two fellowships, one in Gastroenterology and Hepatology at SUNY Downstate Medical Center / The Brooklyn Hospital Center in Brooklyn, New York and another in Advanced Therapeutic Endoscopy at Indiana University Medical Center in Indianapolis, Indiana.

Prior to joining Mount Sinai South Nassau, Dr. Gress was Clinical Chief of the Division of Digestive and Liver Diseases, Chief of Endoscopy and Interventional Endoscopy and Professor of Medicine at Columbia University Medical Center in New York, NY. He was also an attending physician at New York Presbyterian Hospital in New York, NY.

Rashmi R. Advani, MD
Dr. Rashmi Advani is an Interventional and Bariatric Endoscopist who specializes in the endoscopic management of obesity and pancreaticobiliary diseases. Dr. Advani is the Director of Bariatric Endoscopy at Mount Sinai’s Center for Interventional Endoscopy and Assistant Professor of Medicine at the Icahn School of Medicine at Mount Sinai. Dr. Advani is triple board-certified in Gastroenterology, Obesity Medicine, and Internal Medicine. Dr. Advani obtained her medical degree at SUNY Downstate College of Medicine in Brooklyn, NY and completed internal medicine residency at Montefiore Medical Center in Bronx, NY. Dr. Advani completed general gastroenterology training at Stony Brook Hospital in NY and interventional gastroenterology at Cedars Sinai Medical Center in Los Angeles, California.

Dr. Advani is passionate about improving physical/mental wellness and creating equal access to care for her patients. She contributes to efforts that improve medical education, promote gender equity in medicine, and advance research in Gastroenterology. Her work is well-recognized and is published online and on her various social media platforms that are geared to provide easy access to evidence-based information on gastroenterological diseases. Dr. Advani also is a source for career mentorship to trainees at her local institutions and to hundreds of premedical and medical students across the country. Dr. Advani is published in peer-reviewed journals and has authored over 25 manuscripts (original, abstracts, book chapters). She serves on various committees and leadership roles for gastroenterological organizations such as American Society for Gastrointestinal Endoscopy (ASGE), Scrubs and Heels, and Women in Endoscopy (WIE).

Bhanu Singh, MD
Bhanu Singh, MD is an interventional gastroenterologist. He is board certified in internal medicine and gastroenterology. Dr. Singh earned his medical degree from American University of Antigua College of Medicine, he completed a residency at the Icahn School of Medicine at Mount Sinai Elmhurst Hospital Center in New York, NY. He went on to complete two fellowships, first in gastroenterology and hepatology at Icahn School of Medicine at Mount Sinai Elmhurst Hospital Center and then went on to complete an advanced therapeutic endoscopy fellowship at the Virginia Commonwealth University in Richmond, VA.

Steven Friedman, MD
Steven J. Friedman, MD, is board certified in gastroenterology and internal medicine. He earned his medical degree from The University of Michigan Medical School, Ann Arbor, and completed his internal medicine residency and gastroenterology fellowship at Northwestern University, McGraw  Medical Center, in Chicago, IL.

Stephen Mulrooney, MD, FACG
Stephen Mulrooney, MD, FACG Stephen Mulrooney, MD, FACG, Director of Motility, Mount Sinai South Nassau, brings to his patients over thirty years of experience as a gastroenterologist. He is a graduate of the accelerated six-year Biomedical Program of RPI and Albany Medical College. After residency at St. Vincent’s Medical Center in Manhattan, he did his fellowship in gastroenterology at New York Medical College. He served as a Major in the United States Air Force, where he was Chief of Endoscopy at Robert L. Thompson Hospital, Fort Worth, Texas. He has authored numerous publications in gastroenterologyand has been an active faculty participant in fellowship programs. His areas of expertise include GERD, esophageal motility disorders, esophageal manometry, video capsule endoscopy, 24-hour pH studies, BRAVO,  anorectal motility disorders, endoscopy, and colonoscopy. He is board certified in gastroenterology and internal medicine.

Joel Loewenstein, MD
Joel Loewenstein, MD is board certified in internal medicine as well as gastroenterology. He obtained his medical degree from SUNY Downstate School of Medicine. He completed a residency at Kings County Medical Center and fellowship at Mount Sinai Medical Center. Dr. Loewenstein is a gastroenterologist in Long Beach, New York and has been in practice for more than 20 years.