Colon and rectal cancer
Prevention and screening
The risk of developing cancer of the colon or rectum (colorectal cancer) increases with
age. Most cases (93%) occur in people 50 and older.
But there is good news. Screening tests are very effective in helping to prevent this
type of cancer from ever happening. Screening also allows your doctor to find and treat
any colorectal cancer that may be in its
earliest stages.
Important facts about colorectal cancer:
In addition, we now have a lot of
information about things you can do to
reduce your risk of getting this type
of cancer.
Screening tests
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More than 1/3 of people who die from
colorectal cancer could have been saved by
having a screening test.
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Colorectal cancer is the second leading
cause of death from cancer in the US.
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Most people with polyps have no symptoms.
Some people with colorectal cancer have no
symptoms.
Some type of regular screening for
colorectal cancer is recommended for
 Men and women of any racial or ethnic group
everyone starting at age 50. Some
can get colorectal cancer.
people should begin screening earlier.
Talk with your doctor about starting screening earlier than age 50 if you’ve had:
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a close relative who has had colorectal cancer or polyps
colitis or another bowel disease
bleeding from the rectum
stomach pain
a change in bowel habits
unexplained weight loss
The most common screening tests are listed here. Talk with your doctor about which
of these tests makes sense for you. It’s important to understand that your doctor will
do everything possible to make sure you remain as comfortable as possible during these
tests. Remember - the valuable information that these tests provide could save your life!
Fecal Occult Blood Test
Recommended once a year
Sometimes, blood can be passed in very small amounts in the bowel movement (or
stool). This is called “fecal occult blood.” You can test for fecal occult blood yourself
at home using a special kit. The kit comes with instructions on how to test the bowel
movement for blood. You do the test three times, on three different bowel movements.
With some kits you read the results yourself, with others you mail the kits to your
doctor.
If there is blood in the stool, it does not mean you have cancer. Usually the blood is
caused by something other than cancer. Blood in the stool just means that more tests are
needed to find out what is causing the bleeding, and to make sure it is not cancer.
Doing this test every year is an important part of screening, but it is not enough by
itself. It must be used along with tests that examine the colon itself. These tests are
explained below.
Colonoscopy
Recommended every 10 years. Also may be
recommended as a follow-up exam if there is an
abnormality on another screening test.
In this test, the doctor uses a lighted tube (about the
size of a finger) to look at the entire colon. Normally,
you are given heavy sedation for this procedure so
that you do not feel any discomfort. You are asked to
follow special preparations clean out your bowels
before the test. (It’s very important to follow these
instructions exactly, or your doctor may not be able
to see all the areas of your colon properly.)
During the test, the doctor is looking for polyps or
early signs of colorectal cancer. (Most of the growths
found during colonoscopy are not cancer.) Small
polyps and/or small cancers can often be removed as part of the procedure. If cancer is
found, you can begin treatment right away. Treatment for colorectal cancer is most
effective when it is started early. If you have polyps, your doctor will tell you how they
will be treated or followed to make sure cancer doesn’t develop. For example, you may
need another colonoscopy in five years or less.
Research is now being done to determine if colonoscopy should be done more
frequently than every 10 years. Other studies are looking at easier ways to examine the
entire colon.
Flexible Sigmoidoscopy
Recommended every 5 years
This is a test that is similar to a colonoscopy, but allows your doctor to examine only
the rectum and lower part of the colon. You have this test in a doctor’s office, clinic, or
hospital. The doctor may give you a laxative or enema to take the night before the
procedure to clean out the lower part of your colon.
As with colonoscopy, polyps and/or areas of cancer may be seen and/or removed.
If any polyps or cancer are found, your doctor will likely recommend you have a
colonoscopy to examine the rest of your colon.
Double contrast barium enema
Some doctors might recommend a double contrast barium enema. This is a special x-ray
of the intestines that is done in a clinic or hospital. It shows an image of the rectum and
the entire colon. Barium is put into the rectum using an enema, and it creates an outline
around polpys and other growths so that they can be seen.
If something is found during the barium test, a colonoscopy is then needed. So most
doctors advise skipping this procedure and having a colonoscopy instead.
Things you can do to help prevent colon cancer
Research has shown that there are things you can do to reduce your risk of colorectal
cancer. To reduce your risk:
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Get at least 30 minutes of physical activity each day.
Over 
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Eat less red meat – no more than 2-3 servings a week.
Eat 5 or more servings of fruits and vegetables each day.
Take a multivitamin with folate every day.
Keep a healthy weight.
Drink less than one alcoholic drink a day.
Don’t smoke.
Please discuss this information with your health care provider. Ask any questions you
have about your own risk for colorectal cancer. If you’d like a referral to a doctor at
Beth Israel Deaconess Medical Center, please call 617-667-5356.
This material was prepared by clinicians at Beth Israel Deaconess Medical Center. It is produced and distributed by The Beth Israel
Deaconess Learning Center. ©2006, Beth Israel Deaconess Medical Center. All rights reserved.
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