Patient education: Colon polyps (The Basics)

What are colon polyps? — Colon polyps are tiny growths that form on the inside of the large intestine (also known as the colon) (figure 1).

Polyps are very common. About a third to half of all adults have them by the time they are 50 years old. They do not usually cause symptoms. But some polyps can be or become cancer, so doctors sometimes remove them.

What are the symptoms of colon polyps? — Colon polyps do not usually cause symptoms.

How do doctors find colon polyps? — Doctors usually find colon polyps when they are doing screening tests to check for colon or rectal cancer. Cancer screening tests are tests that are done to try and find cancer early, before a person has symptoms.

The screening tests for colon and rectal cancer include:

●Colonoscopy – Before having a colonoscopy, you will get medicine to help you relax. Then, a doctor puts a thin tube into your anus and advances it into your colon (figure 2). The tube has a camera attached to it, so the doctor can look inside your colon. The tube also has tools on the end, so the doctor can remove pieces of tissue, including polyps. After polyps are removed, they usually go to a lab to be tested for cancer and other problems.

●Sigmoidoscopy – A sigmoidoscopy is similar to a colonoscopy, but takes less time and requires less preparation. This test looks only at the first part of the colon, and a colonoscopy looks at the whole colon.

●CT colonography (also known as virtual colonoscopy) – For a virtual colonoscopy, you have a special kind of X-ray taken, called a "CT scan." This test creates pictures of the colon. If a CT colonography test shows that something might be wrong with the colon, doctors must follow up with a colonoscopy.

●Stool test – "Stool" is another word for "bowel movements." Stool tests check for blood or abnormal genes in samples of stool. If a stool test shows that something might be wrong with the colon, doctors must follow up with a colonoscopy to find out if there are polyps or cancer in the colon.

●Capsule colonoscopy – Rarely, your doctor might do something called a "capsule" colonoscopy. For this test, you swallow a special capsule that contains tiny wireless video cameras. If this test shows that something might be wrong with the colon, doctors must follow up with a colonoscopy.

How are colon polyps treated? — Doctors remove polyps using the same tools they use for a colonoscopy. They can remove polyps either by snipping them off with a special cutting tool, or by catching the polyps in a noose (figure 3).

Most polyps can be removed during a colonoscopy. But sometimes, large polyps need to be removed at a later time, either with another colonoscopy or with surgery.

What happens after I have polyps removed? — It depends:

●You might need to have a colonoscopy every few years to check for more polyps. In some people, polyps come back.

●If you have the kind of polyps that could become cancer, your doctor will want to remove them as they appear.

●If the polyps you had removed were the kind that could become cancerous, people in your family might need to be checked for polyps and colorectal cancer earlier than if you did not have polyps.

●Depending on your situation, your doctor might suggest genetic testing. This can show if your polyps are related to a specific gene that runs in families. If so, they might recommend other tests that can be done to prevent cancer or find it early.

Can colon polyps be prevented? — To reduce your chances of getting polyps or colon cancer:

●Eat a diet that is low in fat and high in fruits, vegetables, and fiber.

●Lose weight, if you have excess weight.

●Do not smoke.

●Limit the amount of alcohol you drink.

More on this topic

Patient education: Colon and rectal cancer screening (The Basics)
Patient education: Cancer screening (The Basics)
Patient education: Colonoscopy (The Basics)
Patient education: Familial adenomatous polyposis (The Basics)
Patient education: Low-fiber diet (The Basics)

Patient education: Colon polyps (Beyond the Basics)
Patient education: Screening for colorectal cancer (Beyond the Basics)