Colorectal Cancer Screening

NYU Langone’s Colon Cancer Screening and Prevention Program features highly trained gastroenterologists who provide high-quality colonoscopy procedures in a comfortable environment.

Screening refers to testing that is done before symptoms develop. Screening for colorectal cancer allows your doctor to detect cancer early, when it is highly curable. Some screening tests, including colonoscopy, also help prevent cancer by detecting and removing growths, called polyps, some of which can become cancerous over time.

Experts believe that most colorectal cancers start as a polyp. Over time, some types of polyps—such as an adenoma or adenomatous polyp—can turn into cancer. Detecting and removing a precancerous polyp can help prevent colorectal cancer. 

In addition, when found very early, colorectal cancer is highly curable. Colorectal polyps and early cancers often cause no symptoms, which is why screening is important.

Most colorectal cancers occur in people age 50 and older, but younger people can also develop the disease. Colorectal cancer affects both men and women and people of all ethnic backgrounds. About 70 percent of colorectal cancers develop in people who have no family history of the condition. 

People who are at average risk for colon cancer—meaning they have no risk factors—need to begin screening at age 50. 

NYU Langone doctors recommend one of the following six tests for those at average risk.

Tests that detect polyps and cancers:

  • colonoscopy every 10 years
  • flexible sigmoidoscopy every five years
  • CT colonography every five years

Tests that primarily detect cancer:

  • fecal occult blood test with high sensitivity for cancer, every year
  • fecal immunochemical test with high sensitivity for cancer, every year
  • stool DNA test (how often the test should be performed has not been determined yet)

People who have certain risk factors should start screening at a younger age with colonoscopy. These risk factors include having a personal or family history of colorectal polyps or colorectal cancer; a personal or family history of a genetic colorectal cancer syndrome; or a personal history of inflammatory bowel disease

NYU Langone doctors can help you determine when you should start getting screened, and can recommend an appropriate screening approach for you. 


A colonoscopy is the most comprehensive screening test for colon cancer. For those at average risk, it is recommended every 10 years, starting at age 50. 

Colonoscopy allows for the examination of the entire colon and rectum. It also enables the doctor to detect and remove precancerous polyps immediately. This means a colonoscopy can be used to prevent and detect colorectal cancer. 

Right before your colonoscopy, most people receive an intravenous sedative that causes them to become relaxed or fall asleep during the procedure. During the colonoscopy, your NYU Langone gastroenterologist—a doctor who specializes in screening for, diagnosing, and treating conditions of the gastrointestinal tract—threads a narrow, flexible tube called a colonoscope into the rectum and through the entire colon, or large intestine. The colonoscope has a small camera at its end that allows the doctor to view and examine the lining of the colon and rectum.  

The doctor can identify and remove polyps using a wire loop with an electric current, which is placed through the colonoscope. He or she can also take samples, or biopsies, of suspicious growths or tissue in the colon and rectum. Polyps and other growths are sent to a pathologist, who examines the tissue under a microscope.

Based on your test results and your risk factors, your gastroenterologist can tell you when you need another colonoscopy or, if necessary, recommend further treatment. If you are at average risk for colorectal cancer and your colonoscopy is normal, your next colonoscopy is most likely in 10 years.

Because of the medication used to relax you during the procedure, someone needs to escort you home afterward.


Before a colonoscopy, your doctor provides you with instructions for a bowel preparation—often called “the prep”—that helps to clean out the colon and rectum before the procedure.

Most bowel preps involve consuming a clear liquid diet and taking a laxative regimen by mouth, starting the day before the procedure. It is important to complete the bowel prep to ensure that your colon and rectum are clean. This helps the doctor to detect any polyps or early cancers during the procedure. 

Improving Detection of Polyps and Early Cancers

Colonoscopy is a highly effective test, and NYU Langone gastroenterologists are dedicated to studying and offering the latest advances in technology to help make this procedure even more effective in detecting polyps and early cancers. 

For example, full-spectrum endoscopy, or FUSE®, uses a colonoscope with three tiny cameras at the tip. While a traditional colonoscopy provides doctors with a 170-degree view of the colon and rectum, full-spectrum endoscopy offers an expanded 330-degree view. This may enhance the doctor’s view, thereby allowing for increased detection of polyps that may be hidden behind folds in the colorectal wall.

Another new technology is cuff-assisted colonoscopy, or Endocuff, which involves the use of a disposable device that fits on the end of a colonoscope. The device resembles a tiny hairbrush, with soft, flexible, finger-like projections. These projections allow doctors to flatten folds on the wall of the colon and rectum, potentially improving their ability to find polyps located behind these folds.

Another technology being studied by NYU Langone gastroenterologists is balloon-assisted colonoscopy. This technique involves using a colonoscope with a balloon fitted onto its tip. The balloon is inflated to help doctors flatten the folds of the colon and rectum, potentially making polyps easier to spot and remove. 

Other Advances in Colonoscopy Screening 

Other advances that may be used along with a screening colonoscopy include capsule endoscopy. This test, which is recently approved by the U.S. Food and Drug Administration (FDA), is available for the rare person whose colonoscopy cannot be completed in its entirety. For these people, a colon capsule endoscopy may be used to view the parts of the colon that were not examined. 

The test involves swallowing a vitamin-size camera pill that takes pictures on its way through the digestive system. These images are transmitted to a data recorder and are downloaded for viewing by the doctor.

In addition, NYU Langone gastroenterologists offer a same-day, non-oral colon irrigation option for people who cannot tolerate the bowel prep drink before a colonoscopy. While the traditional bowel prep drink is started the day before a colonoscopy, the colon irrigation prep takes about 45 minutes and is done the same day as your procedure.

Flexible Sigmoidoscopy  

Another option for colorectal cancer screening is a flexible sigmoidoscopy, which allows your doctor to view the lining of the rectum and the bottom portion of the colon, the sigmoid colon. 

During this procedure, the doctor places a small, flexible tube with a camera on its end into the rectum and sigmoid colon. If any potentially precancerous polyps are detected, the doctor can remove them. Abnormal tissue may be biopsied for further testing. This procedure often does not require any sedative medications, although they may be an option for some people.

A flexible sigmoidoscopy allows for both the prevention and early detection of colorectal cancer, but only in the rectum and sigmoid section of the colon. The test does not involve examination of the entire colon. It is recommended every five years if no abnormal results are found. If a polyp or other abnormal result is found, a follow-up colonoscopy is needed. 

CT Colonography 

NYU Langone physicians and researchers were at the forefront of developing CT colonography. Sometimes called virtual colonoscopy, this procedure uses three-dimensional, cross-sectional X-ray images of the colon and rectum to detect polyps and cancers.

The day before the procedure, you need a laxative bowel prep, just as you would for a traditional colonoscopy.

During the procedure, the doctor places a small tube in the anus and pumps in air to inflate the colon and rectum. Once the colon and rectum are filled with air, CT scans are taken. No sedation is required during the procedure. 

CT colonography enables your doctor to examine the entire colon and is considered effective in the detection of both polyps and colon cancer. This test is usually performed by a radiologist. It is recommended every five years if no abnormal results are found. If polyps or other abnormal findings are detected, a follow-up colonoscopy is required to remove them.

High-Sensitivity Fecal Occult Blood Test 

A fecal occult blood test, also called FOBT, is another option for colon cancer screening. The FOBT test is a take-home kit and must be designated as having high test sensitivity for cancer, such as Hemoccult SENSA.  

The FOBT is used to check for blood in the stool that’s not visible to the naked eye. Blood in the stool can be a sign of cancer or another condition. To prepare for this test, you may need to avoid certain medications and foods because they can affect the results. 

An FOBT test should be performed at home using the kit given to you by your doctor. The test involves collecting multiple samples of your stool and placing them on testing cards and into a container provided by your doctor. You can usually mail the stool samples to a laboratory, where they’re analyzed. 

This screening test is used primarily to help detect, not prevent, colorectal cancer. Many different FOBT tests are available. Only those that have a high test sensitivity for cancer should be used for colorectal cancer screening. 

If FOBT is part of your screening plan, it needs to be done every year. If blood is detected, a follow-up colonoscopy is required to determine the source of the bleeding.

Fecal Immunochemical Test 

A fecal immunochemical test, also known as an FIT test or FIT kit, is another stool test. It detects blood in the stool but does not require that you avoid any medications or foods beforehand.

Most FIT tests are considered more sensitive than FOBT tests. As with the FOBT test, the stool sample is collected at home and is sent to a laboratory for analysis. 

Many different FIT tests are available; only those done as a take-home kit and those having a high sensitivity for cancer should be used for colorectal cancer screening. This test is used primarily to help detect colorectal cancer, and does not prevent cancer. 

If the FIT test is recommended by your doctor as part of your screening plan, it needs to be repeated every year. If the results indicate that there is blood in the stool, a follow-up colonoscopy is required to determine the source of the bleeding.

Multitarget Stool DNA Stool Test 

A DNA stool test looks for both blood and DNA, or genetic material, shed by cancerous tumors and some polyps in the stool. While DNA stool tests are a recommended screening option, the newly FDA-approved multitarget DNA stool test has not yet been added to the national recommendations. However, it may be included in the near future.

This new test does not require you to stop any medications or avoid certain foods. It is done as a take-home kit, in which a stool sample is collected and mailed to the laboratory for analysis.

The multitarget DNA test is highly sensitive for detecting cancers but is not as sensitive for finding polyps. Because the test is new, researchers have not yet determined how often it should be performed. If the test results are abnormal, a follow-up colonoscopy is required to examine the colon and rectum.

If your doctor detects an abnormality on any of these colon cancer screening tests, a follow-up colonoscopy is required. In addition, if you have certain risk factors—such as a family history of colon polyps or cancer or a personal history of inflammatory bowel disease—you need to be screened by colonoscopy.

More Colorectal Cancer Resources

Meet Our Doctors

NYU Langone specialists provide care and support throughout your entire healthcare journey.

Browse Doctors