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Colorectal Cancer Screening Methods
click on test name to read more
| Type of Test |
Accuracy |
How Often (if results are negative) |
Advantages |
Disadvantages |
Fecal Occult Blood Test
(FOBT) |
Does not find any polpys
Finds about 60% of cancers |
Once a year |
Inexpensive, covered by most insurance
Test sample collected in privacy at home
Strong evidence this screening reduces mortality
|
Limited accuracy
May be unpleasant, you collect your own stool sample
Need to restrict diet for 3 days
If the test shows blood, a followup colonoscopy is needed
|
| Flexible Sigmoidoscopy combined with FOBT |
Finds 0% of polyps or cancer in the top part of the colon
Finds about 73% of small polyps in the last third of the colon only
Finds about 97% of large polyps in the last third of the colon only
Finds about 85-97% of cancers in the last third of the colon only
|
FlexSig every 5 years, when combined with yearly FOBT |
Moderate cost, covered by most insurance
Many primary care physicians can do the test in their office
Evidence suggests this screening reduces mortality
|
Cannot find cancers in the first third of the colon, where 40% of colon cancers occur
Requires laxative and/or enema preparation
No food on the day of the test
May be embarassing for some people
Could cause mild to moderate discomfort
Small risk of perforation or bleeding
Needs to be combined with FOBT
The FOBT needs to be done once a year
If polyps are found, a full colonoscopy is needed
|
| Air Contrast Barium Enema (ACBE) |
Finds about 67% of small polyps
Finds about 82% of large polyps
Finds about 84% of cancers
|
Every 5 years |
Screens full colon |
Need to follow a liquid diet for one day before, no food and laxative preparation the day of the test
May be embarassing for some people
Could cause moderate discomfort
A follow-up colonoscopy will need to be done to remove any polyps or cancer the test finds
Does not provide an adequate exam of the rectum and may miss rectal polyps
|
| Colonoscopy |
Finds about 79% of small polyps
Finds about 85% of large polyps in the entire colon
Finds about 96.7% of cancers
|
Every 10 years |
Screens full colon
No discomfort or pain with sedation
|
Need to follow a liquid diet for one day and laxative preparation before the test
May be embarassing for some people
Small risk of perforation or bleeding
|
| Type of Test |
Accuracy |
How Often (if results are negative) |
Advantages |
Disadvantages |
|
Does not find any polpys
Finds about 60% of cancers |
Once a year |
Inexpensive, covered by most insurance
Test sample collected in privacy at home
Strong evidence this screening reduces mortality
|
Limited accuracy
May be unpleasant, you collect your own stool sample
Need to restrict diet for 3 days
If the test shows blood, a followup colonoscopy is needed
|
Any blood in your stool or bowel movement could be a sign that you are bleeding from inside your
colon or rectum. Colon cancers often bleed so the blood in your stool could be a sign that you
have a colon or rectum cancer, however, many things can cause bleeding.
Blood in your stool cannot always be seen with the naked eye. A Fecal Occult Blood Test
(FOBT) is a lab test to see if there are traces of blood in your stool.
Your doctor gives you a kit to collect a stool sample at home. You put a small amount of stool
on a card and mail it to the lab. Your doctor will tell you how to collect the sample and watch
what you eat for three days before the test (for example, no red meat).
The lab sends the FOBT results to your doctor. A positive test does not mean you have colon
cancer. If you get a positive test, you will need a colonoscopy to make sure the bleeding is not
coming from colon or rectum cancer.
If you get a negative test, this does not mean you have no colon cancer. The FOBT may not find
all cancers. Colon cancers can bleed on and off and you may do the test when the cancer is not
bleeding.
Also, the FOBT will not find the small growths (polyps) that usually do not bleed. Finding and
removing a polyp before it becomes cancer is a good way to prevent colon cancer.
| Flexible Sigmoidoscopy | Air Contrast Barium Enema | Colonoscopy | Back to top
| Type of Test |
Accuracy |
How Often (if results are negative) |
Advantages |
Disadvantages |
|
Finds 0% of polyps or cancer in the top part of the colon
Finds about 73% of small polyps in the last third of the colon only
Finds about 97% of large polyps in the last third of the colon only
Finds about 85-97% of cancers in the last third of the colon only
|
FlexSig every 5 years, when combined with yearly FOBT |
Moderate cost, covered by most insurance
Many primary care physicians can do the test in their office
Evidence suggests this screening reduces mortality
|
Cannot find cancers in the first third of the colon, where 40% of colon cancers occur
Requires laxative and/or enema preparation
No food on the day of the test
May be embarassing for some people
Could cause mild to moderate discomfort
Small risk of perforation or bleeding
Needs to be combined with FOBT
The FOBT needs to be done once a year
If polyps are found, a full colonoscopy is needed
|
Flexible Sigmoidoscopy (Flex Sig) allows the doctor to check in the lower part of the colon
and rectum for signs of cancer and growths (polyps).
This test is very similar to a colonoscopy but instead of examining the entire colon,
the Flex Sig only looks at the last third where most cancers are found. The doctor uses
a long flexible camera to look at the inside of your rectum and lower part of the colon.
Tissue samples and polyps can be removed at the same time. If lesions are found, you will
need a more extensive test which will cause some moderate discomfort without sedation.
Your colon has to be empty for the test so you will not be allowed to eat anything the day
before, only liquids, and you will need to take laxatives. The doctor will put small puffs
of air inside your colon to expand it and give a better view.
You will not need to be sedated for the Flex Sig because it doesn't go as far up as a
colonoscopy does. However, because the Flex Sig doesn’t examine the entire length of your
colon, it could miss any polyps or cancers growing in the upper part.
The air that was puffed inside your colon will need to be passed as gas. The results of the
Flex Sig will be mailed to your home about a week after the test. FOBT will need to be
repeated every year.
Fecal Occult Blood Test | | Air Contrast Barium Enema | Colonoscopy | Back to top
| Type of Test |
Accuracy |
How Often (if results are negative) |
Advantages |
Disadvantages |
|
Finds about 67% of small polyps
Finds about 82% of large polyps
Finds about 84% of cancers
|
Every 5 years |
Screens full colon |
Need to follow a liquid diet for one day before, no food and laxative preparation the day of the test
May be embarassing for some people
Could cause moderate discomfort
A follow-up colonoscopy will need to be done to remove any polyps or cancer the test finds
Does not provide an adequate exam of the rectum and may miss rectal polyps
|
A barium enema is an x-ray test that looks for things that are wrong in the intestines such
as colon cancer. During the test a soft, chalky, liquid dye (called barium) is put in the
colon. The dye is also metallic which shows up on an x-ray. The ACBE can find polyps and cancer
in the colon but does not examine the rectum.
Before the test your intestines will need to be empty and free of stool. The day before
the test you will be put on a liquid diet that includes water, clear juices, Jell-O, and
soup broth. After midnight on the day before the test you should not eat or drink anything.
Your doctor will tell you to take a laxative the night before the test and you may need to
have an enema.
On the day of the test you will have x-rays done to be sure your intestines are empty. An
enema tube is put in your rectum and the metallic dye is passed through the tube into your
intestines. Air will be puffed into your intestines. Some people will have a moderate amount
of discomfort and feel the urge to have a bowel movement as the dye and air are put inside
the intestines.
You may be asked to turn in different positions and hold you breath to get the best x-ray
pictures. The person taking the x-rays may also press on your stomach to move your colon around
to get the best pictures.
Once the test is done you can go back to your usual diet and regular day. You may be asked to
drink extra water for 24 hours after the test. Your stools will be white or pale for several
days after the test as your body gets rid of the chalky dye. The results will be mailed to
your home about three to five days later.
Fecal Occult Blood Test | Flexible Sigmoidoscopy | | Colonoscopy | Back to top
| Type of Test |
Accuracy |
How Often (if results are negative) |
Advantages |
Disadvantages |
|
Finds about 79% of small polyps
Finds about 85% of large polyps in the entire colon
Finds about 96.7% of cancers
|
Every 10 years |
Screens full colon
No discomfort or pain with sedation
|
Need to follow a liquid diet for one day and laxative preparation before the test
May be embarassing for some people
Small risk of perforation or bleeding
|
A colonoscopy is a test that lets the doctor check out the inside of your colon and rectum.
Colonoscopy can find and remove any early signs of cancer growths and polyps on the lining
of your colon or rectum.
Your colon needs to be completely empty when the colonoscopy is done. You only drink tea,
fruit juice, clear soda and Jello (not red Jello) the day before, and you also need to take
laxatives and drink nothing after midnight the night before the test.
The doctor will tell you what to do about any daily medications you take. Some medications
will need to be stopped five days before: others can be taken with small sips of water early
in the morning on the day of the test. You will also need to bring a list of all medications
with you and make sure to tell the doctor if you have any health problems.
Although the exam only takes about 45 minutes, you should plan to be at the doctor's office
for about four hours. You will feel drowsy after the test and be a little forgetful, and your
reflexes will be slower because of the medications used. This means you need to have a
friend or family member come with you and drive you home. You will also need to take the
day off work but you will be O.K to return to work the next day.
The doctor will give you medications to make you sleepy and drowsy. The medications contain a
pain killer and will make you forget most of the exam. Colonoscopy rarely causes much pain.
You will be hooked up to monitors, asked to lay on your side on the examining table, and
then the doctor will put a long flexible tube like a telescope into your rectum. This allows
the doctor to see inside your entire colon and get tiny samples of tissue (biopsy) or polyps.
The doctor puffs a little air into your colon to make it wider and easier to examine. If tissue
or polyps are removed they will be sent to the lab to be examined under a microscope.
After about half an hour, when you feel more awake, you get a snack and the nurse will make
sure you can get to the bathroom to pass gas. You may have some cramping and bloating because
of the air puffed into you during the exam. This usually goes away within a few hours. You will
then change back into your street clothes, get some follow up instructions and leave. For your
own safety, you will not be allowed to leave in a cab; you must have someone drive you home.
When you get home you can eat whatever you like. The colonoscopy results will be mailed to
your home about a week after the test.
Fecal Occult Blood Test | Flexible Sigmoidoscopy | Air Contrast Barium Enema | | Back to top
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