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About Riverdale Gastroenterology & Liver Diseases

We are a four-physician practice of gastroenterologists serving the Bronx area for 35 years. Riverdale Gastroenterology & Liver Disease offers a full array of gastroenterology services such as Hemorrhoids, Colonoscopy, Hepatitis, Colitis, Crohn’s Disease and many more!

We combine state-of-the-art medicine with cutting-edge technology (typically seen at elite hospitals). We provide some of the highest-level care for gastrointestinal, liver disease and colorectal cancer prevention, detection and screening in the Bronx area. At the same time, we stay committed to providing professional, personal and compassionate care while obtaining complete patient satisfaction and comfort during the patient’s visit.

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Colonoscopy

A colonoscopy is now the gold standard used to detect or prevent individuals from getting colon cancer. Adults starting at age 45 years are strongly recommended to have a colonoscopy or some other test to screen for colon cancer.

Capsule Endoscopy

During the procedure, a patient swallows a vitamin-sized pill with a camera inside (pill camera). Transported smoothly and painlessly through the GI tract by the body’s own natural peristalsis, the video pill capsule transmits images of different parts of your intestine, such as the small intestine and the esophagus.

ERCP

An endoscopic retrograde cholangiopancreatography, more commonly known as ERCP, is an endoscopic procedure that is also combined with X-rays. ERCP is very much like a typical upper GI endoscopy; however, your gastroenterologist will inject a dye during the procedure, which highlights problems in certain digestive organs through X-ray technology.

Flexible Sigmoidoscopy

A sigmoidoscopy is an internal exam of the lower part of the large intestine (colon) using a short, thin, flexible, lighted tube with a camera at the tip. This procedure helps determine the cause of abdominal pain, rectal bleeding, changes in bowel habits, chronic diarrhea, and other intestinal problems.

Hemorrhoid Treatments

Two of the most common treatments for hemorrhoid removal are hemorrhoid banding, which cuts off blood flow to the hemorrhoid, and infrared coagulation (IRC) therapy, which uses infrared light to shrink and shrivel hemorrhoids. The treatment method depends highly upon whether the hemorrhoids are external (around the anus) or internal (in the rectum).

Upper Endoscopy

An endoscopy is a very common and safe procedure that is used to examine the esophagus, stomach, and upper part of the small intestine, known as the duodenum, to get a closer look at what may be causing symptoms.

Celiac Disease

Celiac disease is an autoimmune disease where a patient’s immune system abnormally responds to the ingestion of gluten. It is estimated that 1 in 100 people worldwide is affected by celiac disease. However, up to 2.5 million people in the United States may have celiac disease and not know it, as the symptoms range from mild to severe.

Constipation

Constipation is defined as having a bowel movement fewer than three times per week. With constipation, stools are usually hard, dry, small in size, and difficult to eliminate. Some people who are constipated find it painful to have a bowel movement and often experience straining, bloating, and the sensation of a full bowel.

GERD

Gastroesophageal reflux disease (GERD) is a more serious form of gastroesophageal reflux (GER) which is common. GER occurs when the lower esophageal sphincter (LES) opens spontaneously, for varying periods of time, or does not close properly, and stomach contents rise up into the esophagus.

Hemorrhoids

Hemorrhoids are swollen veins in the anal canal. This common problem can be painful and can be caused by too much pressure on the veins in the pelvic rectal area. Normally, tissue inside the anus fills with blood to help control bowel movements, but if you strain or sit on the toilet a long time to move stool, the increased pressure causes the veins in this tissue to swell and stretch.

Inflammatory Bowel Disease + Crohn's Disease & Ulcerative Colitis

Inflammatory bowel disease (IBD) encompasses a set of gastrointestinal diseases where parts of the digestive tract are chronically inflamed by a dysfunctional interaction immune system. Hereditary factors and an abnormal interaction between microorganisms and the immune system are felt to play a role.

Irritable Bowel Syndrome

It is estimated that 10 to 15 percent of Americans have Irritable Bowel Syndrome (IBS). IBS is a functional GI disorder that refers to a group of symptoms that affect the digestive tract, often resulting in abdominal pain, bloating, or cramping. However, some people with IBS have no symptoms at all.

What Our Patients Say About Us

Dr. Isadore Gutwein is very knowledgeable, interested in the whole person and warm. I have been seeing him for decades and I know he is different from most other practitioners.
Anne C.
Anne C.
Nice setting. Friendly staff. Michael S. Ader, M.D. was very thorough in explaining the process. He is a real down to earth person. No complaints.
Seymour K.
Seymour K.
Doctor Jeremy Gutwein was very caring and took his time to find out what was going on with me, He make me feel like I was part of his family, I am very happy to know that there is still good human out there.
Nestor A.
Nestor A.
Dr. Stein was very nice and a straight shooter very thorough.
Luis R.
Luis R.
I have been with Dr. Sable for many years. He is excellent and very knowledgeable! But what is very important, he is a humanitarian, down to earth and genuinely interested in his patients. You can't get better than that!
Mark
Mark
I've been using and recommending dr. Isadore Gutwein for over 20 years. Very knowledgeable, great skills, and a very caring doctor.
Anonymous
Anonymous
I went to see Dr. Ader today for the first time. I sat mesmerized as he explained to me in detail the Colonoscopy procedure using medical terminology with humor thrown in. He is one of the best doctors i have ever met. I would recommend him to anyone and everyone.
Anonymous
Anonymous
have been Dr. Gutwein patient for years and all I can say is that he is a excellent professional and the best GI Doctor. His team are respectful and kind at all times.
Libia
Libia
Not too long ago I went in for my first G.I. Doctors appointment with Dr. Stein. As a new patient I was very nervous and didn’t know what to expect. Thankfully Dr. Stein was very friendly, making me feel comfortable as soon as I sit down. The fact that he took the time to listen to me very careful and explained everything with reasonable details was amazing. Very knowledgeable, kind and patience. He gave me options and tough my things I didn’t know. I would highly recommend Dr. Estein.Thank you so much.
Shianny M.
Shianny M.
Dr. Robbert sable, is genius, he fixed my hemorrhoids issue
Mohamed
Mohamed

Blogs
IBS

How to Relieve IBS Pain

The abdominal pain and cramping of irritable bowel syndrome (IBS) can range from a nagging ache to a flare that stops you in your tracks. If you are searching for

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August 8, 2026
Bloating

How to Stop Bloating After Meals

That tight, swollen, uncomfortable feeling that shows up after eating is one of the most common digestive complaints, and it can turn an enjoyable meal into hours of discomfort. The

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August 1, 2026
Diet

How to Follow an Elimination Diet for IBS

For people living with irritable bowel syndrome (IBS), food can feel like a minefield, with meals sometimes triggering abdominal pain, bloating, and unpredictable bowel habits. A structured elimination diet is

Read More »
July 22, 2026

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Important Notice: Participating Carriers

We are pleased to inform you that our services are covered by a variety of participating insurance carriers. Please review the list of participating carriers to ensure your plan is included. 
 
  • 1199
  • Aetna
  • Cigna
  • Cigna Medicare Advantage
  • Emblem, GHI, HIP
  • Blue Cross Blue Shield Empire
  • NYSHIP/UHC Empire Plan
  • Healthfirst
  • Humana
  • Humana Military/Tricare
  • Independent Practice Association of New York (IPA NY)
  • Magnacare
  • Medicaid
  • Medicare New York
  • Multiplan
  • Oxford
  • United Healthcare
  • WellCare
If you have any questions or need assistance, don't hesitate to contact us.