What patients are saying
Overall rating
4.88
Average wait time
4.56
Bedside manner
4.91
“Th entire office was so friendly and Dr Marshak was very attentive, understanding, and patient. Very happy with my visit ”
Amanda A.September 12, 2025
“The office staff was very welcoming. The doctor’s assistants were very warm and friendly. Dr. Marshak was very knowledgeable and listened to my issues asking pertinent questions. He devised a plan to further diagnose any issues I might have. I felt very at ease during my visit and I have every confidence I am on the right road to recovery.
I will highly recommend Dr. Marshak to my friends and family.”
Paul R.July 29, 2024
About Dr. Jarred Marshak
Skilled with the intricacies of gastroenterology, Dr. Jarred Marshak received his medical degree from the American University of the Caribbean School of Medicine. Subsequently, he completed a residency in internal medicine at Winthrop-University Hospital, followed by a fellowship in gastroenterology at NYU Winthrop Hospital.
Based in Wantagh, NY, Dr. Marshak is excited to bring his knowledge to Long Island Gastroenterology Specialists. Patients visit him for a host medical concerns, such as stomach pain, acid reflux, diarrhea, and hemorrhoids. A skilled physician, he is also certified by the American Board of Internal Medicine.
In addition to pursuing his clinical career, Dr. Marshak has published articles in prestigious journals that focus on various topics in his field of specialization. He is also an active member of the American College of Gastroenterology and the American Society for Gastrointestinal Endoscopy.
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In-network insurances
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Medicare
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Areas of expertise
This doctor's experience enhances their expertise in similar cases. Below are the conditions or surgeries they treat most frequently.
Colonoscopy
Acute gastrointestinal bleeding
Acute stomach inflammation/infection
Upper GI endoscopy
Stomach and duodenal inflammation
Acute hemorrhoids
Colonoscopy
Acute gastrointestinal bleeding
Acute stomach inflammation/infection
Upper GI endoscopy
Office location
Education and background
Practice names
Hospital affiliations
- Mercy Medical Center
- The Mount Sinai Hospital
- NYU Langone Health
Board certifications
- American Board of Internal Medicine
- Gastroenterology (Internal Medicine)
Education and training
- Medical School - American University of the Caribbean School of Medicine, Doctor of Medicine
- Winthrop-University Hospital, Residency in Internal Medicine
- NYU Winthrop Hospital, Fellowship in Gastroenterology
- Winthrop-University Hospital: Decicco Brenda (Internship)
Professional memberships
- American College of Gastroenterology
- American Society for Gastrointestinal Endoscopy
Languages spoken
- English
Provider's gender
Male
NPI number
1538417027
Patient reviews
All reviews have been submitted by patients after interacting with the practice.
Overall rating
4.88
Wait time
4.56
Bedside manner
4.91
Your trust is our top concern, so providers can't pay to alter or remove reviews. We also don't publish reviews that contain any private patient health information. Learn more here
181 reviews
Most relevant
Th entire office was so friendly and Dr Marshak was very attentive, understanding, and patient. Very happy with my visit
September 12, 2025Amanda A.Verified patient
Dr M was great! listened to all my concerns and answered all my questions and working on treatment
November 21, 2025Jarrett B.Verified patient
When I came in and by my fold 24 early they make sure that I was taking care of right away
January 14, 2026Adriena M.Verified patient
Staff friendly. Minimal wait time. Felt rushed, Dr. spoke very fast, seemed rushed and disinterested.
Less than 1 year agoInitials hidden
The whole staff was amazing …. Would definitely recommend
Dr. Marshak made me feel comfortable and was very informative
March 14, 2022Eileen P.Verified patient
Dr Marshak is the best. He listens and is so easy to understand. I have been going to Dr. Marshak for over a year now.
More than 1 year agoInitials hidden
Great listener, didn't feel rushed, I was seen in about 15 minutes. The staff were all very friendly
More than 1 year agoInitials hidden
Dr. Marshak diagnosed my problem and referred to me a colleague which provided relief on the same day. Thank you!
More than 1 year agoInitials hidden
Doctor was very knowledgeable and understanding
Explained how to approach situation
Very comfortable
June 27, 2023Marliyn D.Verified patient
Dr. Marshak was excellent. He took the time to explain everything to me. I would highly recommend him.
More than 1 year agoLA
Very kind and helpful as I was extremely nervous. Feel comfortable continuing my treatment with him.
More than 1 year agoInitials hidden
Very professional office, and Johnny parking lot man,greets you and makes it an easy visit
March 31, 2023Gene H.Verified patient
Dr. Marshak had great bedside manner and listened to all of your concerns.
May 21, 2024Abigail O.Verified patient
Dr Marshak was very good dealing with the patient who has hypoxia and anxiety issues.
January 13, 2023Michael C.Verified patient
Excellent visit. Very helpful and approachable. Made the visit very relaxed and comfortable.
More than 1 year agoJK
I thought that he took his time and was interested in me and my medical needs.
More than 1 year agoInitials hidden
Friendly staff. Dr Marshack answered all my questions and a very nice person.
February 12, 2020Minerva K.Verified patient
Dr. Marshal was knowledgeable and professional , I would highly recommend .
October 12, 2020Eric J.Verified patient
Welcoming and friendly staff. Dr Marshak was wonderful, easy to talk to
February 19, 2021Initials hidden
Very impressed with the doctor, and the office. Glad we picked the office.
More than 1 year agoLG
Great place very nice doctor. Knew what he was doing and very compitent.
February 15, 2019Adam H.Verified patient
I had a great experience from reception to the medical staff
April 23, 2023Donald H.Verified patient
Dr and staff made me very comfortable and dr was excellent
August 27, 2022Patricia L.Verified patient
Very professional, explained everything I needed to know.
More than 1 year agoLG
Very helpful and did not spend more time than expected.
More than 1 year agoInitials hidden
Very good bedside manner, excellent staff, clean office.
More than 1 year agoRD
Really great experience.
January 13, 2026Initials hidden
Outstanding staff..
June 26, 2025Mahmoud H.Verified patient
Excellent ! Professional and efficient!
November 11, 2024Patricia L.Verified patient
Quick and easy.
August 13, 2024Gina A.Verified patient
The office staff was very welcoming. The doctor’s assistants were very warm and friendly. Dr. Marshak was very knowledgeable and listened to my issues asking pertinent questions. He devised a plan to further diagnose any issues I might have. I felt very at ease during my visit and I have every confidence I am on the right road to recovery.
I will highly recommend Dr. Marshak to my friends and family.
July 29, 2024Paul R.Verified patient
Excellent staff and doctor!
April 24, 2024Patricia L.Verified patient
Great doctor staff was awesome
March 18, 2024Irina C.Verified patient
I felt comfortable with Dr Marshak.
August 1, 2023Daniel M.Verified patient
very friendly, and professional
July 18, 2023Jennifer S.Verified patient
Dr. Marshak was really thorough and made sure I felt comfortable throughout the appointment. The staff was also super friendly! Would highly recommend to everyone!
May 1, 2023Initials hidden
Friendly people, great covid protocols
April 16, 2023Tanya V.Verified patient
This was one of the nicest doctor officers I've ever been to. Everyone was extremely friendly. if you need a GI doctor I would highly recommend them.
September 9, 2022Christopher M.Verified patient
Very friendly, took the time to get to know my situation. Explained how the procedure would work in great detail. I felt comfortable with every aspect of my visit.
June 8, 2022Tyler F.Verified patient
The doctor and office staff were incredibly kind and friendly. From the moment I pulled into the parking lot (literally), I felt more comfortable and less anxious about the visit!
More than 1 year agoInitials hidden
Great wait time and bedside manner!
February 22, 2022Barbara B.Verified patient
Very efficient and thorough
January 3, 2022Initials hidden
great dr. did my endoscopy. very professional
More than 1 year agoInitials hidden
I started having stomach issues. Went to Dr. Marshak due to time urgency. He performed my colonoscopy, I was diagnosed with UC mild. Took the recommended medication. A week later my condition was 1000x worse. Went to a doctor my family used for a second opinion. I received a call from Dr. Marshak's office because my new doctor had reached out for the colonoscopy photos, but the call was asking if I was getting a second opinion or switching doctors, I told them I was switching. They never sent them, my doctors office proceeded to reach out two other times, nothing. It took me having to threaten them with legal actions to finally send the documents. Very unprofessional, wouldn't recommend them to anyone.
More than 1 year agoInitials hidden
Nice office. Dr. Marshak is great. The thing that stands out is the gentleman who checks patients in while you're in the parking lot. He goes above and beyond to make your visit pleasant and even watches traffic for you as you're leaving the parking lot.
August 11, 2021Jason V.Verified patient
Great office environment - very safe and clean. Staff was wonderful, attentive and communication was excellent (both internally and with patients). Dr. Marshak is clear and happy to share detailed information until all questions were addressed. Everyone was very professional and processes streamlined.
June 4, 2021Gary M.Verified patient
Excellent service. Thorough. Efficient.
March 24, 2021Erich S.Verified patient
Great!
February 19, 2021John G.Verified patient
I highly recommend Dr. Marshak. He listened to everything you had to say and is very thorough on his exams. Keep up the great work Dr.
More than 1 year agoAbigail O.Verified patient
Great experience. Friendly and helpful staff.
January 20, 2021Initials hidden
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How soon can I make an appointment with Dr. Jarred Marshak?
Generally, Dr. Jarred Marshak has appointments available on Zocdoc within 1 week. You can see Dr. Marshak's earliest availability on Zocdoc and make an appointment online.
Is Dr. Jarred Marshak accepting new patients?
Dr. Jarred Marshak generally accepts new patients on Zocdoc. You can see Dr. Marshak's earliest availability on Zocdoc and schedule an appointment online.
Does Dr. Jarred Marshak accept my insurance?
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Can I make an appointment with Dr. Jarred Marshak online?
Yes, you can make an appointment online with Dr. Marshak using Zocdoc. It’s simple, secure, and free.
Which hospital is Dr. Jarred Marshak affiliated with?
Dr. Jarred Marshak is affiliated with Mercy Medical Center, The Mount Sinai Hospital, and NYU Langone Health.
What practice does Dr. Jarred Marshak work with?
Where is Dr. Jarred Marshak's office located?
Dr. Jarred Marshak's office is located at 2155 Wantagh Ave, Wantagh, NY 11793.
Which board certifications does Dr. Jarred Marshak have?
Dr. Jarred Marshak is certified by American Board of Internal Medicine and Gastroenterology (Internal Medicine).
What are common reasons for patients to see Dr. Jarred Marshak?
Dr. Jarred Marshak frequently sees patients for Abdominal Pain, Colonoscopy, Gastroenterology Consultation, Hemorrhoids, and Illness. You can see other visit reasons for Dr. Jarred Marshak on their profile.
What languages does Dr. Jarred Marshak speak?
Dr. Jarred Marshak speaks English.
How do patients rate Dr. Jarred Marshak in reviews?
181 patients have reviewed Dr. Jarred Marshak. The overall rating for this doctor is 4.88/5. They have a 4.91/5 rating for bedside manner and a 4.56/5 rating for wait time. You can read individual reviews and ratings on their profile.