GANJ – Rutherford Location in Rutherford
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Office in Rutherford
  • Areas of Practice:
  • Gastroenterology

GANJ – Rutherford Location

About Us

Gastroenterology Associates of New Jersey (GANJ) is an integrated group practice comprised of a team of highly skilled gastroenterologists. As part of our dedication to complete care, our board certified physicians and professional staff will effectively evaluate, diagnose and treat acute and chronic gastrointestinal conditions and diseases.

With locations throughout northern & central New Jersey, our multidisciplinary practice offers coordinated and comprehensive services with an emphasis on personalized care for patients of all ages and activity levels. In addition, our practice is affiliated with five ambulatory surgery centers where our advanced procedures are performed in a warm, comfortable environment on an outpatient basis.

Speaking about issues relating to one’s gut health isn’t easy. The physicians here at GANJ help put their patients at ease so that they create a treatment plan for whatever the situation.

For more information on our premier physicians, locations or services, contact us today.

Our Doctors

Joseph M. Roth, MD

Dr. Joseph M. Roth is a gastroenterologist at Gastroenterology Associates of New Jersey (GANJ). Prior to his position at GANJ, Dr. Roth was the Chief of Medicine and Chief of Gastroenterology at St. Mary’s Hospital in Passaic, NJ.

Education & Training
  • He completed a fellowship in gastroenterology at the University of Connecticut in Farmington, CT and his residency and internship in internal medicine at Lenox Hill Hospital in New York, NY.
  • In addition, he received his medical degree from the University of Pittsburgh in Pittsburgh, PA.
  • He received his bachelor’s degree from Rutgers University in New Brunswick, NJ, graduating with high honors.
  • Board Certifications
  • American Board of Internal Medicine – Internal Medicine
  • American Board of Internal Medicine – Gastroenterology
  • Honors and Awards
  • Awarded Castle Connolly Top Doctors 2023
  • Awarded Top Doctor by New Jersey Monthly
  • Awarded Top Doctor by Inside New Jersey
  • Professional Memberships
  • American College of Physicians
  • American Gastroenterological Association
  • Frank Ruiz, MD

    Dr. Frank Ruiz is a gastroenterologist at Gastroenterology Associates of New Jersey.

    Education & Training
  • Dr. Ruiz completed a fellowship in gastroenterology, a residency and internship in internal medicine as well as his medical degree at Rutgers New Jersey Medical School in Newark, NJ.
  • In addition, he received his Bachelor of Science degree from Seton Hall University in South Orange, NJ.
  • Honors and Awards
  • Awarded Castle Connolly Top Doctors 2023
  • Kenneth G. Zierer, MD

    Dr. Kenneth G. Zierer is a gastroenterologist at Gastroenterology Associates of New Jersey. He is triple board certified in internal medicine, pediatrics and gastroenterology by the American Board of Internal Medicine. Dr. Zierer also offers FibroScan®: painless, accurate, noninvasive way to assess liver health

    Education & Training
  • Dr. Zierer completed a fellowship in hepatology, a combined residency and internship program for internal medicine and pediatrics as well as his medical degree from Rutgers New Jersey Medical School in Newark, NJ.
  • In addition, he received his bachelor’s degree from George Washington University in Washington, D.C.
  • Board Certifications
  • American Board of Internal Medicine – Internal Medicine
  • American Board of Internal Medicine – Gastroenterology
  • American Board of Internal Medicine – Pediatrics
  • Honors and Awards
  • Awarded Castle Connolly Top Doctors 2023
  • Awarded Bergen County’s Top Doctors 2023
  • Our Services

    Serving multiple counties in northern and central New Jersey, Gastroenterology Associates of New Jersey (GANJ) utilizes the latest techniques of the industry to effectively diagnose and/or treat an array of acute and chronic gastrointestinal conditions. With a team approach and an extensive network of experienced physicians, GANJ is able to provide complete care for disorders of the digestive system for patients of all ages. All procedures are performed in the comfort of the office or in one of our advanced ambulatory surgery centers.

    Procedures we perform include:

    For more information on the procedures we perform or to schedule an appointment, contact us today.


    At Gastroenterology Associates of New Jersey, our specialized team of physicians and staff has years of combined experience providing care for acute and chronic gastrointestinal conditions. With an advanced network and a team approach, we provide an efficient diagnosis, customized treatment and preventive care plan for the individual needs of you and your family.

    Conditions we treat include:

    For more information on the conditions we treat or to schedule an appointment with one of our specialists, contact us today.

    Our Office
    Phone: 201-842-0020
    Fax: 201-842-0010
    Monday: 9:00 AM - 5:00 PM
    Tuesday: 9:00 AM - 5:00 PM
    Wednesday: 9:00 AM - 5:00 PM
    Thursday: 9:00 AM - 5:00 PM
    Friday: 9:00 AM - 5:00 PM
    Saturday: Closed
    Sunday: Closed
    Additional Contact Information

    Are you currently a patient of GANJ? Click here to access your encrypted, secure patient portal so you can access information 24/7 from the comfort and privacy of your own home or office.

    Insurance

    Please see below for a full list of our Accepted Insurance Plans:

    • Medicare NJ*
    • Medicaid NJ
    • Aetna PPO/HMO/Medicare
    • Amerigroup
    • Americhoice
    • Amerihealth (HMO/PPO/POS)
    • Empire BCBS
    • Beech Street / Medichoice
    • Humana
    • Cigna (HMO/PPO/POS)
    • Community Care Network
    • Consumer Health Network
    • Devon / Americare
    • Emblem Health (PPO/HMO)
    • First Health
    • Galaxy
    • GHI (PPO/HMO)
    • Healthnet
    • Horizon BCBS of NJ (PPO/HMO/Traditional)
    • Horizon NJ Health
    • Local 825
    • Local 1199 (thru Aetna)
    • Magnacare
    • Health Republic
    • Multiplan
    • “Oxford (Liberty/Freedom/Medicare)”
    • Qualcare (HMO / PPO)
    • Railroad Medicare
    • Tricare
    • “United Healthcare (HMO, PPO, POS, EPO)”
    • VNS
    • Wellcare

    *accepted by all of our doctors

    Please note: This list is not all-inclusive and some of our doctors do not participate in all of these plans. To confirm if the doctor participates, please contact your insurance company directly.