The Importance of Colorectal Cancer Screening

What is Colorectal Cancer?

Despite the fact the colon cancer is the second leading cause of cancer death in the United States, it is actually a common, treatable disease. And while it's easy to feel overwhelmed and frightened by all the testing options, regular screening can indeed save your life.

Colorectal cancer is a disease in which malignant (cancerous) cells form in the inner lining of the colon or rectum. Most colon and rectal cancers originate from benign wart-like growths on the inner lining of the colon or rectum called polyps. While not all polyps end up cancerous, the overwhelming majority of colon cancers start out as polyps. It is for this reason that regular testing for and removal of colon polyps can go a long ways towards preventing colon cancer.

Screening Tests

Screening tests are used to find cancers before they are large enough to cause any warning signs. Because finding cancer early means that you're more likely to be cured, it is important to have appropriate screening tests. Identifying and removing polyps before they become cancerous actually prevents the development of colorectal cancer. The following are some screening tests for colorectal cancer. Your doctor will recommend the test most appropriate for you.

  • Digital Rectal Exam—In this exam, your doctor puts his or her gloved finger into your rectum to find any growths. This exam finds less than 10% of colorectal cancers, and usually is performed along with another screening test.
  • Fecal Occult Blood Test—In this test, your stool is checked for blood that you can't see. If blood is found, another test is done to look for a polyp, a cancer or another cause of bleeding.
  • Flexible Sigmoidoscopy—In this test, your doctor uses a thin, flexible, hollow tube—connected to a tiny video camera with a light on the end—to examine your rectum and the lower part of your colon.
  • Double-Contrast Barium Enema—For this test, you are given an enema (injection of fluid into the rectum) with a liquid that makes your colon show up on an x-ray. Your doctor looks at the x-ray to find abnormal spots in your entire colon.
  • Colonoscopy—A thin, flexible tube connected to a video camera is put into your rectum, and the doctor looks at your whole colon. The tube can also be used to remove polyps and cancers during the exam. While similar to a flexible sigmoidoscopy, a colonoscopy can view the entire colon.

Who is at Risk?

Colorectal cancer is more common in older people, so doctors usually screen people 50 years of age and older. Some people have risk factors that make them more likely to get colorectal cancer at a young age. Screening should begin earlier in these people. You should begin screening at a younger age if any of the following are true about you:

  • Have had colorectal cancer or large polyps in the past
  • Have a close relative (brother, sister, parent or child) who has had colorectal cancer before age 60
  • Have ulcerative colitis or Crohn's disease
  • Have a hereditary colon cancer syndrome.

If you are in one of these groups, you may also need to be tested more often than a person who doesn't have risk factors for colorectal cancer.

Talk to your family doctor to decide which screening tests you should have and how often you should be screened. If you don't have any risk factors for colorectal cancer, you will probably have your first screening test around 50 years of age.

What are the symptoms of colorectal cancer?

Symptoms of colorectal cancer vary depending on the location of the cancer within the colon or rectum, though there may be no symptoms at all. The prognosis tends to be worse in symptomatic as

  • Bleeding from your rectum
  • Blood in your stool or in the toilet after you have a bowel movement
  • A change in the shape of your stool
  • Cramping pain in your lower stomach
  • A feeling of discomfort or an urge to have a bowel movement when there is no need to have one