Please note that as of May 24, 2023, Dr. Parikh is no longer with Gastroenterology Associates of New Jersey (GANJ).

Patients can contact the River Edge office directly at (201) 489-7772 if they prefer to see a physician at that location, or call 888.452.0022.

Thank you.

Patricia Kraycinovich has been in the medical field for more than 15 years. She is both a licensed RN and APN. She received a Bachelor of Science in psychology from Saint Peter’s College, and Bachelor of Science in Nursing (BSN) from Ramapo College, and a Master of Science in Nursing (MSN) in Adult-Gero Advanced Nurse Practitioner from Rutgers University.

One of the most rewarding and fulfilling aspects of working in this field, she says, is having a role in both patients’ diagnosis as well as their treatment plan. Prior to joining the medical team at GANJ, Mrs. Kraycinovich worked with single, private practitioners as well as at Columbus Hospital LTACH and Englewood Hospital and Medical Center.

Dr. Parthiv Raval is a Gastroenterology Specialist with more than 35 years of medical experience. He received his undergraduate degree from Kasturba Medical University in 1987. He completed his internal medicine residency at Catholic Medical Center, New York, where he was Chief Resident.

His gastroenterology fellowship was completed at Catholic Medical Center in 1995. Dr. Raval was the former Chief of Gastroenterology at Barnet Hospital, Paterson, NJ. He is currently an attending physician at St. Mary's Hospital, Passaic; and St. Joseph's Hospital, Paterson. He has received numerous awards including multiple Patients' Choice Awards and Compassionate Doctor Recognition awards. Dr. Raval resides in Totowa, NJ, and enjoys traveling, swimming, and spending time with his family.

Dr. Raval's office is located at 1030 Clifton Avenue, Clifton, NJ.  To schedule an appointment, call 973.614.9700


Dr. Aakash Aggarwal is a member of Hackensack Digestive Disease Associates. His clinical focus is General gastroenterology, esophageal disorders (including acid reflux, dysphagia, achalasia, etc) Quality improvement, and colon cancer screening and prevention. He is board-certified in Gastroenterology and Internal Medicine. He is also actively involved in research and has presented at various national and international conferences.

He completed his residency in Internal Medicine at the State University of New York Health Science Center in Syracuse, NY, and his Fellowship in Gastroenterology/Hepatology at the University of Connecticut, School of Medicine in Farmington, CT.

Dr. Aggarwal is a member of the various societies including the American College of Physicians, New York Society for GI endoscopy, American Foregut society, Medical Society of the State of New York; American College of Gastroenterology; American Association for Study of Liver Diseases; Crohn’s and Colitis Foundation of America.

Dr. Aggarwal is a member of Hackensack Digestive Disease Associates

Dr. Coburn earned his medical degree from New York Medical College, where he was inducted into the Alpha Omega Alpha Honor Society and the Gold Humanism Honor Society. He completed his internship and residency in Internal Medicine at New York Presbyterian – Weill Cornell Medical Center.

His fellowship in general Gastroenterology was completed at Dartmouth Hitchcock Medical Center, where he also obtained additional expertise in the management of inflammatory bowel disease.

Dr. Coburn has co-authored multiple publications in peer-reviewed journals.

He is a member of Hackensack Digestive Disease Associates.

Awarded Castle Connelly Top Doctor 2023.

In 2022, Dr. Coburn was recognized as a Rising Star by Castle Connelly.

Alyssa Parrish is an AANP board certified Family Nurse Practitioner. Alyssa completed her bachelors of science in Nursing at Marywood University in 2013 and then went on to complete her Masters Of Science In Nursing at Fairleigh Dickinson University in 2018. During her training she was inducted into Sigma Theta Tau International Nursing Honor Society.

Alyssa has worked as a registered nurse in Emergency/Trauma for the past 8 years and in primary care as a Nurse Practitioner for the past 2 years. Alyssa loves making a difference in medicine and joined GANJ with hopes to assist in researching, educating, and managing patients with acute and chronic conditions so they can live life at greatest potential.

Dr. Steven Leibowitz has practiced with his father, Dr. Arnold Leibowitz, since 1989 and is a member of Hackensack Gastroenterology Associates. Affiliated with Hackensack University Medical Center, the group utilizes the most advanced diagnostic and therapeutic modalities in managing inflammatory bowel disease, colorectal and GI malignancies, peptic and motility disorders and hepatobiliary diseases.

A graduate of Georgetown University Medical School and trained at Cornell University-North Shore University Hospital and Memorial Sloan-Kettering Cancer Center in New York, Dr. Leibowitz prides himself on blending his expertise with quality time in providing care for his patients.

Dr. Steven Leibowitz was awarded Top Doctor in 2009 published in New Jersey Monthly magazine and serves alongside his father as Consultants in Gastroenterology to the New York Football Giants.

Call us at 201-489-7772 if you have any questions or would like to schedule an appointment.

Awarded Castle Connolly Top Doctors 2023
Awarded Bergen County's Top Doctors 2023

Dr. Richard Lin graduated from Yale University with a bachelors in science in Molecular Biophysicis and Biochemistry before completing his medical degree at New York University.  Afterwards, he continued his internal medicine training at UCLA-Harbor in California, and then returned to NYU to finish his gastroenterology fellowship. He is board certified in both internal medicine and gastroenterology. He has published abstracts in palliative metallic stenting as well as inflammation’s role in colon cancer. Dr. Lin is a member of Hackensack Gastroenterology Associates.

While Dr. Lin treats a wide variety of gastrointestinal and liver conditions, including advanced biliary endoscopy, metallic stenting and capsule endoscopy, he has a particular interest in colon cancer as well as Asian American gastrointestinal issues including stomach cancer and Hepatitis B.

Call us at 201-489-7772 if you have any questions or would like to schedule an appointment.

Awarded Castle Connolly Top Doctors 2023

George Nikias is a graduate of New York Medical College. He completed a residency in Internal Medicine at North Shore University Hospital and Memorial Sloan-Kettering Cancer Center followed by a fellowship in Hepatology at the Mayo Clinic in Rochester Minnesota and a fellowship in Gastroenterology at Memorial Sloan-Kettering Cancer Center. Dr. Nikias is a member of Hackensack Gastroenterology Associates.

Dr. Nikias has received numerous distinctions, including being named one of the metro area’s Top Doctors by Castle-Connoly every year since 2007. He was named to the list of  Top Doctors in Gastroenterology by New York  Magazine in 2014. His areas of expertise include advanced endoscopy, including ERCP and Endoscopic Ultrasound with Fine Needle Aspiration as well as the management of complex liver disease.

Dr. Nikias also offers FibroScan®: painless, accurate, noninvasive way to assess liver health. Click here to learn more

It is Dr. Nikias’ belief that an individual’s understanding of their illness is the first step in achieving wellness. He looks forward to educating his patients and helping them realize optimal digestive health.

Call us at 201-489-7772 if you have any questions or would like to schedule an appointment.

Awarded Castle Connolly Top Doctors 2023
Awarded Bergen County's Top Doctors 2023