Our Staff

MMG Board Certified Gastroenterologists

All of our professionals at Middlesex Monmouth Gastroenterology maintain the highest levels of accreditation and pursue ongoing education to stay abreast of the latest trends in Gastroenterology.

For more than 75 years, certification by the American Board of Internal Medicine (ABIM) has stood for the highest standard in Internal Medicine and its 19 subspecialties and has meant that internists have demonstrated to their peers and to the public that they have the clinical judgment, skills, and attitudes essential for the delivery of excellent patient care. ABIM is not a membership society, but a non-profit, independent evaluation organization. Our accountability is both to the profession of medicine and to the public.

The brief descriptions below are designed to familiarize you with our staff's training, professional credentials and work experience.


Steven C. Nadler, M.D., F.A.C.G.

Dr. Nadler received his medical degree from UMDNJ, New Jersey Medical School in Newark, NJ. He completed his Internal Medicine Internship and Residency, as well as his Gastroenterology Fellowship training at UMDNJ, Robert Wood Johnson University Hospital, New Brunswick, NJ. He is ABIM Board Certified in both Internal Medicine and Gastroenterology. He is a Fellow of the American College of Gastroenterology.

Since 1993, Dr. Nadler has provided Gastroenterology services to patients in Middlesex and Monmouth Counties. He has expertise in all areas of digestive diseases, with a special interest in endoscopic procedures, inflammatory bowel disease (ulcerative colitis and Crohn’s disease) and hepatitis.

Arthur J. Geller, M.D., F.A.C.P., F.A.C.G.

Dr. Geller received his medical degree from Columbia University in NY. He completed his Internal Medicine training at the North Shore University Hospital, Memorial Sloan-Kettering Cancer Center program of the Cornell Hospitals. He completed his Gastroenterology Fellowship at UMDNJ, Robert Wood Johnson University Hospital, New Brunswick, NJ. Dr. Geller is Board Certified in both Internal Medicine and Gastroenterology and is a Fellow of the American College of Physicians and the American College of Gastroenterology.

As a Wilson-Cook Scholarship recipient, Dr. Geller studied advanced endoscopic procedures at Georgetown University Medical Center in Washington, D.C. He also served as the therapeutic endoscopist at the liver transplant center at Albert Einstein Medical Center in Philadelphia. He has held teaching appointments at the University of Florida, Temple University in Philadelphia and Georgetown Medical School. Dr. Geller has authored chapters in medical textbooks on Gastroenterology and has authored several articles for medical journals.

Dr. Geller has been named an “N. J. Top Doc” for his commitment to excellence in Gastroenterology for 2016, 2017 and 2018.

Colin C. Brown, M.D., M.S.P.H

Dr. Brown received his medical degree from Temple University in Philadelphia. He completed his medical Internship and Residency training at Boston Medical Center and his Gastroenterology Fellowship training at the University of Alabama at Birmingham. He is Board Certified in Internal Medicine and Gastroenterology.

Dr. Brown practiced Internal Medicine during his Fellowship years. He has co-authored papers on colorectal neoplasia and gastrointestinal angiodysplasia and has contributed to an upcoming textbook on Gastroenterology and Hepatology.

Kunal Gupta, M.D., M.B.A.

Dr. Gupta received his medical degree from the UMDNJ-Robert Wood Johnson Medical School in New Jersey, where he also completed his medical internship and residency training in Internal Medicine with Distinction in Research.  He completed the three-year Gastroenterology Fellowship program at the University of Vermont-Burlington with advanced training in Endoscopic Ultrasound (EUS) and Endoscopic Retrograde Cholangiopancreatography (ERCP).

Dr. Gupta is Board-Certified in both Internal Medicine and Gastroenterology.

Dr. Gupta currently serves as the Chief of Gastroenterology and the Co-Director of Advanced Endoscopy at CentraState Medical Center in Freehold, NJ.

Robert S. Aaron, M.D.

Dr. Aaron completed his Advanced Gastroenterology Fellowship training at Maimonides Medical Center in New York.

His medical residency training was completed at the Lahey Hospital and Medical Center in Massachusetts.

Dr. Aaron is ABIM board certified in Internal Medical and Gastroenterology.

Prior to joining MMG, Dr. Aaron practiced Gastroenterology in Stoneham, MA.

He has a special interest in chronic liver disease and fecal microbiota transplantation. He also has expertise in all facets of general Gastroenterology.

Office Hours

Monday - Friday:

7:00 am - 4:00 pm

Saturday, Sunday:


Endoscopy Center of Monmouth County

222 Schanck Road Suite: 100

Freehold, NJ 07728

(732) 845-0990

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