What Are Screenings Like

What to expect from colonoscopy and other screening tests.

What Are Screenings Like?

There are several tests that you can have to screen for colorectal cancer (CRC) or for precancerous polyps.

Screening means that your colon and rectum are being checked to see if there are any signs of cancer or of cellular changes that could lead to cancer. Screening is done as part of preventive care, and not because a patient is having symptoms.

If you are having symptoms of colorectal cancer, then your test likely will be diagnostic (following up on symptoms to determine the cause) rather than screening.

Your doctor can help you decide which test is right for you. If you are considered to be at average risk for CRC, you will have more choices. For people who are considered to be at higher risk, colonoscopy may be the only appropriate screening test.

Colonoscopy is the only test that can not only look for cancer, polyps and other precancerous lesions. It also is the only test during which polyps can actually be removed, preventing them from possibly progressing to cancer.

Several of the available tests require a full bowel cleansing beforehand, which your doctor's office will explain to you and help you manage.

If you do have a test other than colonoscopy, and there is a positive result (a suspicion of polyps or cancer), then you will need to have a colonoscopy to follow up and take a thorough look at your colon and rectum. Information about all of the screening options is found on the "Which Screening Is for Me?" page.

On this page, we will talk about colonoscopy.

ASGE has a helpful video if you are preparing to have your first colonoscopy.

About Colonosopy

Colonoscopy is considered the "gold standard" of CRC screening. Here we provide in-depth answers to common questions about the procedure.

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About Colonoscopy

Why is colonoscopy performed?

Colonoscopy is used to directly see the lining of the colon to look for conditions such as cancer, colitis (inflammation of the colon) and diverticular disease (small pockets on the colon). Colonoscopy may also be used to investigate unexplained diarrhea, bleeding and anemia. Sometimes colonoscopy is used to evaluate an abnormality seen on other imaging tests such as CT scans and barium studies.
What preparation is required?

Your doctor will tell you what sort of diet and cleansing routine to follow before the test. Your cooperation in this preparation will allow the gastroenterologist to get the clearest and most accurate views possible. In general, the "prep" involves drinking a special cleansing solution, along with plenty of clear fluids, and taking special laxatives by mouth. Be sure to tell your doctor about conditions such as diabetes, heart and/or kidney disease. You should plan your prep diet ahead of time and check with your doctor if you have any questions.
Can I take my regular medications?

Most medications can continue to be taken as directed, but some can interfere with the preparation or the examination. You should tell your doctor about all your medications, especially aspirin products, anti-inflammatory medications such as ibuprofen, pain medicines, blood thinners, insulin or iron supplements. Don't forget to mention "over the counter" supplements that you may be taking as well. You should also tell your doctor if you normally require antibiotics before dental procedures, since you may have the same needs before your colonoscopy.
Is colonoscopy painful?

A colonoscopy is a very comfortable exam because it is usually done with intravenous sedation. This means that you will be in a very sleepy state during the procedure. Most patients are not even aware that the procedure happened when they wake up.
What happens during a colonoscopy?

Most doctors perform colonoscopy in a procedure room with a TV monitor. After your medical history has been reviewed and the medical staff has explained the procedure and answered any questions you may have, you will sign a permission form.

You will then be connected to equipment that monitors your heart rate, blood pressure and oxygen levels. Before the procedure, an IV will be started in your arm so that sedatives and other medications can be administered.

You will lie on your side or back and once sedated, your doctor slowly advances the scope through your colon. Air or carbon dioxide is slowly introduced into the colon, under low pressure to allow expansion for a careful examination of the lining. Water may also be used to wash away any fecal residue. There also is a suction device attached to the scope to remove any remaining fluid left over from the prep.

The scope is slowly and carefully advanced around the colon to the point where the large intestine joins the small intestine in the right lower region of the abdomen, near the appendix. If polyps are found they are removed. Any abnormal tissue is biopsied. The procedure usually takes 20 to 60 minutes, although you should plan on being in the endoscopy unit for a total of two to three hours to account for preparation, procedure and recovery.
What happens if the colonoscopy shows something abnormal?

One of the main advantages of colonoscopy over other types of tests is that it can sample abnormal areas of the colon for further evaluation. Sometimes your doctor will take biopsies in areas that look normal to the naked eye. If you are having a colonoscopy because of internal bleeding, your doctor may decide to cauterize or clip the bleeding vessels with special instruments passed through the scope. Such procedures rarely cause any pain. If a polyp is found, it is removed and then sent to the pathology lab for microscopic evaluation.
Why is polyp removal (polypectomy) performed if found during the colonoscopy?

One of the most common uses of colonoscopy is for screening and prevention of colon cancer. Finding a potentially precancerous polyp is important as most cancers can be prevented by removing the polyp before it has a chance to become cancerous. Polyps vary in size from about the size of a pea to several inches and are usually harmless. However, some polyps can become cancerous and for this reason, they are usually removed during the colonoscopy. This procedure is called a "polypectomy." In most cases, your doctor cannot tell which polyps may eventually become cancerous, so the whole polyp, or at least a sample of it, needs to be examined under a microscope. The ability to safely and painlessly remove such growths before they become cancerous has made colon cancer one of the most preventable cancers in the world.
What happens after a colonoscopy?

Your physician will explain the results of the examination, but you will probably have to wait for the results of any biopsies. If you received sedatives during the exam, you will need to have a friend or relative take you home. Even if you feel alert after the procedure, your judgment and reflexes could be impaired for the rest of the day. Because your doctor used air to inflate the colon when looking at the lining of the colon, you might experience some cramping or bloating. This feeling should disappear once you start passing gas. Although you should be able to eat shortly after the examination, your doctor might restrict your diet and activities if a procedure, such as removing a polyp, was performed.
What are the possible complications or risks of colonoscopy?

Colonoscopy and the special techniques mentioned above are very safe when performed by specially trained doctors with experience performing these types of procedures. As with any medical procedure, even in expert hands, unintended events may happen, and you need to be aware of the potential consequences.

There is a small risk of having a reaction to any of the drugs given during the exam. In most cases, medications are available to counteract these side effects. A rare complication is tearing or perforation of the lining of the intestine. Should this occur, surgery may be needed to seal the injury. Another risk is bleeding, usually at the site of a biopsy or polyp removal. Most cases of bleeding stop without treatment or can be controlled at the time of procedure.
What sort of things should concern me after the colonoscopy?

Although complications after colonoscopy are uncommon, it is important to be aware of early signs that something is wrong. You should not hesitate to contact your doctor if you feel any symptoms that are not typical for you (such as abdominal pain, dizziness, fever, chills, or blood in your stools) during the two weeks following your colonoscopy.

For questions about this Web site, contact info@asge.org. For questions specifically related to your health and getting screened for colorectal cancer, contact your doctor, or find a GI doctor in your area.

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The Patient Protection and Affordable Care Act

The Patient Protection and Affordable Care Act, passed in 2010, waives the coinsurance and deductible for many colon cancer screening tests, including colonoscopy, sigmoidoscopy and fecal occult blood testing (FOBT). Colonoscopy is a unique screening test because gastroenterologists are able to remove precancerous polyps during the screening procedure. Under Medicare billing rules, removal of any polyp reclassifies the screening colonoscopy as a therapeutic procedure, for which patients will receive a coinsurance bill. This is often unexpected by patients under the impression that deductible or coinsurance charges were waived.

There are efforts ongoing to correct this problem. ASGE, along with the American Cancer Society Cancer Action Network (ACS CAN), and the American Gastroenterological Association (AGA), are advocating that Congress fix this "cost-sharing" problem, which continues to cause confusion for patients and providers. The Removing Barriers to Colorectal Cancer Screening Act of 2012 introduced in March 2012 by Rep. Charlie Dent, R-PA, waives the coinsurance for a screening colonoscopy regardless of whether a polyp or lesion is found. Congressman Dent's bill applies the same rational policy to beneficiary coinsurance. The expectation is that this will eventually be corrected.

Private Insurance

In February 2013, the federal government issued an important clarification on preventive screening benefits under the Affordable Care Act. Patients with private insurance will no longer be liable for cost sharing when a pre-cancerous colon polyp is removed during screening colonoscopy. This ensures colorectal cancer screening is available to privately insured patients at no additional cost, as intended by the new healthcare law. Patients with Medicare coverage must still pay a coinsurance when a polyp is removed as a result of the screening colonoscopy.

Click here for the guidance language provided by the administration. Patients with private insurance should check with their individual providers to learn the details of their coverage and ask about the Affordable Care Act.

Colorectal Cancer Screening Tests Covered by Medicare

In 2000, Medicare started paying for colonoscopy for people age 50 and older. Prior to 2000, Medicare only covered the exam for people at high risk or with symptoms. People on Medicare now have more choices for screening tests.

For people on Medicare, this is what is covered:

Stool blood test (FOBT or FIT) each year for those 50 and over
Flexible sigmoidoscopy (flex-sig) every four years for those 50 and over at average risk
Colonoscopy every two years for those at high risk
Colonoscopy once every 10 years for those 50 and over at average risk
Barium enema with air contrast instead if a doctor believes that it is as good as or better than flex-sig or colonoscopy
Virtual colonoscopy is not covered by Medicare as an initial screening test

Colonoscopy is the most commonly utilized screening test for colon cancer since it has a high yield of detecting precancerous polyps and is able to remove them.