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Colorectal Cancer

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This topic will tell you about the initial testing, diagnosis, and treatment of colorectal cancer. If you want to learn about colorectal cancer that has come back or has spread, see the topic Colorectal Cancer, Metastatic or Recurrent.

What is colorectal cancer?

Colorectal cancer happens when cells that are not normal grow in your colon or rectumClick here to see an illustration.. These cells grow together and form tumors.

This cancer is also called colon cancer or rectal cancer. It is the third most common cancer in the United States. And it occurs most often in people older than 50.

As with other cancers, treatment for colorectal cancer works best when the cancer is found early. Screening tests can detect or prevent this cancer, but only about half of people older than 50 are screened. According to the American Cancer Society, if everyone were tested, tens of thousands of lives could be saved each year.

What causes colorectal cancer?

Most cases begin as polypsClick here to see an illustration., which are small growths inside the colon or rectum. Colon polyps are very common, and most of them do not turn into cancer. But doctors cannot tell ahead of time which polyps will turn into cancer. This is why people older than 50 need regular tests to find out if they have any polyps and then have them removed. And some people who are younger than 50 need regular tests if their medical history puts them at increased risk for colorectal cancer.

What are the symptoms?

Colorectal cancer usually does not cause symptoms until after it has begun to spread. See your doctor if you have any of these symptoms:

  • Pain in your belly
  • Blood in your stool or very dark stools
  • A change in your bowel habits, such as more frequent stools or a feeling that your bowels are not emptying completely

How is colorectal cancer diagnosed?

If your doctor thinks that you may have this cancer, you will need a test, called a colonoscopy (say "koh-luh-NAW-skuh-pee"), that lets the doctor see the inside of your entire colon and rectum. During this test, your doctor will remove polyps or take tissue samples from any areas that don't look normal. The tissue will be looked at under a microscope to see if it contains cancer.

Sometimes another test, such as a sigmoidoscopy (say "sig-moy-DAW-skuh-pee"), is used to diagnose colorectal cancer.

How is it treated?

Surgery is almost always used to treat colon and rectal cancer. The cancer is more easily removed when it is found early.

If the cancer has spread into the wall of the colon or farther, you may also need radiation or chemotherapy. These treatments have side effects, but most people can manage the side effects with medicines or home care.

When you first find out that you have cancer, you may have many feelings. You may feel scared or angry. Or you may feel very calm. There is no "right" way to react. It is normal to have a wide range of feelings. And it is normal for those feelings to change quickly.

Some people find that it helps to talk about their feelings with family and friends. You may also want to talk with your doctor or with other people who have had cancer. Your local American Cancer Society chapter can help you find a support group.

How can you screen for colorectal cancer?

Screening tests can find or prevent many cases of colon and rectal cancer. They look for a certain disease or condition before any symptoms appear. Experts recommend routine colon cancer testing for everyone age 50 and older who has a normal risk for colon cancer. Your doctor may recommend earlier or more frequent testing if you have a higher risk for colorectal cancer. Talk to your doctor about when you should be tested.

These are the most common screening tests:

  • Stool tests that check for signs of cancer:
    • Fecal occult blood test (FOBT)
    • Fecal immunochemical test (FIT)
    • Stool DNA test (sDNA)
  • Sigmoidoscopy. A doctor puts a flexible viewing tube into your rectum and into the first part of your colon. This lets the doctor see the lower portion of the intestine, which is where most colon cancers grow. Doctors can remove polyps during this test also.
  • Colonoscopy. A doctor puts a long, flexible viewing tube into your rectum and colon. The tube is usually linked to a video monitor similar to a TV screen. With this test, the doctor can see the entire large intestine.
  • Computed tomographic colonography (CTC). This test is also called a virtual colonoscopy. A computer and X-rays make a detailed picture of the colon to help the doctor look for polyps.

Frequently Asked Questions

Learning about colorectal cancer:

Being diagnosed:

Getting treatment:

Ongoing concerns:

Living with colorectal cancer:

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