Cancer of the colon is a major health problem in the United
States. It ranks as a leading form of cancer, along with lung
and breast cancer. Importantly, colon cancer is also one of
the most curable forms of cancer. When detected early, more
than 90 percent of patients can be cured. Roughly 150,000 people
develop colon cancer annually and 60,000 succumb to this disease.
Colonoscopy is the procedure of choice for detecting and removing growths from the colon.
Colonoscopy utilizes a relatively thin, long tube with a video chip located at the tip. The system
provides for high resolution color examination of colon. The instruments are equipped with working channels that allow for
the passage of devices that take samples (biopsies) or remove growths (polyps).
The tube is passed through the anus into the rectum and is advanced through the entire colon.
A complete exam is essential and means the scope was passed into the right colon to an area called the cecum.
The colon is like an inverted U in your abdominal cavity. The first area entered is the rectum, then to the left colon
comprised of the sigmoid and descending colon. It continues across the upper abdomen through the transverse colon into
the right colon, called the ascending colon, and into the cecum. The cecum connects to the small intestine referred
to as the terminal ileum. The colon is about 6 to 8 feet long.
The preparation for colonoscopy is often dreaded, but with newer formulations has been made easier. Most
patients maintain a clear liquid diet the day before the test and consume a cathartic substance
that forces several bowel movements until the stool appears clear. The specifics of your colonoscopy
preparation will be provided by your gastroenterologist.
The alternatives to colonoscopy include barium enema x-ray that must be combined with
flexible sigmoidoscopy (a short scope that viwes the rectum and left colon) to properly view the left colon
or virtual colonoscopy. Barium enema is less senstive than colonoscopy for picking up abnormilties. Virtual colonoscopy utilizes CAT scan 3D imaging to reconstruct images of the colon.
It still requires preparation and rectal tube insertion to introduce air to expand the colon. Unfortunately, it
can miss small polyps (less than 0.5 centimeters) and is ususally not covered by insurance.
Both barium enema and virtual colonoscopy do not allow for sampling of colon tissue. If there is an abnormality
with either of these tests, then you will require colonoscopy as a definitive diagnostic test that is
able to sample tissue or remove abnormal growths.
No exam is perfect. Miss rates do occur with colonoscopy and have been reported to occur anywhere from 6-20 percent
of the time.
Routine checking of the stool for hidden or occult blood is used in colon cancer screening on an annual basis for
anyone of average risk 40 years of age or above. Colonoscopy is recommended for average risk persons
beginning at the age of 50. Consult with your doctor about the additional screening guidelines. Remember, any
form of screening is better than none at all.
If you have any alarm symptoms such as rectal bleeding, a change in your bowel pattern, abdominal pain, or unexplained
weight loss, contact your doctor.
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This disease begins in the cells that line the colon. There
now is strong medical evidence that there is an abnormal gene
for colon polyps and cancer that can be passed from parent
to child. The genes within each cell are the hereditary structures
that tell the cell what it should do. It is becoming increasingly
clear that certain of these genes control the growth of the
cells on the lining of the colon. When these controlling genes
are absent, there is a tendency to grow polyps. The cells in
the polyp eventually become uncontrolled and turn into cancer.
Colon cancer also can develop from other conditions, such as
colitis.
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What is Colon Polyp?
A
polyp is a growth that occurs in the colon and other organs.
These growths, or fleshy tumors, are shaped like a mushroom
or a dome-like button, and occur on the inside lining of
the colon. They may be as small as a tiny pea or larger than
a plum. It is important to note that while colon polyps start
out as benign tumors, some polyps, in time, become malignant.
In fact, the larger the polyp, the more likely it is to contain
cancer cells. In most cases, it is a polyp called an adenoma
polyp that develops into colon cancer. The good news is that these growths are often dectected by colonoscopy
and can be safely removed at the same time as detection.
What Are The Risk Factors For
Developing
Colon Polyps and Cancer?
Family history of polyps, cancer, and especially colon
cancer.
Western civilization and diet.
Being over 40 years of age
History of breast cancer
Ulcerative Colitis
Crohn's Disease
In Summary...
Cancer of the colon is a serious but readily detected malignancy. In addition,
early detection promises a particularly high chance of survival. Most colon
cancers start as polyps, which can usually be removed with an outpatient
procedure. Today, much information is available to significantly reduce the
risk of this disease. The essential first step involves action by the patient.
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