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What you need to know about cancer of the colon

When Jay Monahan, husband of well-known television journalist Katie Couric, died from colon cancer in 1998, his death drew nationwide attention to a sobering reality: Cancer of the colon or rectum (also called colorectal or large bowel cancer) often doesn’t cause noticeable symptoms until it has reached an advanced stage. As with most kinds of cancer, colorectal cancer is much more curable when it’s detected early. Here’s what you need to know about early detection.

Blood in the stool, either bright red or very dark in color, is one of the hallmarks of colorectal cancer. If you spot this warning sign, see your doctor immediately. Also see your doctor if any of the following symptoms last for two weeks or more:

  • a change in bowel habits, such as diarrhea or constipation
  • stools that are narrower than usual
  • an urgent, painful need to defecate
  • general stomach discomfort, such as bloating, cramps or gas pains
  • a feeling that the bowel has not been emptied completely
  • unexplained weight loss
  • constant tiredness

Take quick action—but don’t panic, because many of the above symptoms also can be caused by less serious conditions, including ulcers, hemorrhoids and an inflamed colon. Eating something red, such as licorice or beets, also can add a tinge of color to the stool. So don’t automatically assume the worst if you recognize any of these warning signs, but do see a doctor.

Next, you should know that colorectal cancer is best detected before it causes symptoms. You can do that by choosing one of these screening options from the American Cancer Society guidelines. Beginning at age 50:

  • have a fecal occult blood test every year to check for blood in the stool. In this simple and inexpensive test, a small amount of stool is put onto a plastic slide or specially treated paper and analyzed either in the doctor’s office or at a laboratory.
  • have a sigmoidoscopy performed every five years. During this procedure, the physician inserts a thin, lighted, tubular scope into the large bowel through the anus. The scope enables the doctor to check visually for abnormalities in the rectum and lower colon, where more than half of all large bowel cancers occur.
  • have an annual fecal occult blood test along with a sigmoidoscopy every five years. This combination is preferable to either test alone.
  • get a double-contrast barium enema test every five years. Air is pumped into the colon after it is expanded with a chalky substance (barium) and an X-ray is then taken.
  • have a colonoscopy performed every 10 years. This test examines your colon and rectum for any abnormalities using a colonoscope—a long, flexible tube inserted through the rectum. The patient is sedated during the test, which usually makes the procedure painless.

Because the vast majority of colorectal cancers develop in polyps—nubs or stalks of tissue growing inward from the wall of the colon or rectum—removing them can dramatically lower your likelihood of developing the disease in the first place. In fact, studies have shown that removal of these benign growths can cut risk by 90 percent.

You can also reduce your risk of colorectal cancer by adopting a low-fat, high-fiber diet that includes at least five servings of fruits and vegetables a day. One serving equals 1/2 cup of fruit or cooked vegetable, 1 cup of leafy greens, 3/4 cup of juice or 1/4 cup of dried fruit.

In addition, mounting evidence shows that moderate physical activity reduces the risk of this type of cancer. That doesn’t mean you have to be a marathon runner. In fact, you don’t even have to run. Walking briskly for 20 minutes or more a day three times a week appears to be all it takes to reduce significantly your risk of colorectal cancer.