Colon
cancer is a disease in which malignant (cancer) cells form in the
tissues of the colon.
The colon
is part of the body's digestive
system. The digestive system removes and processes nutrients
(vitamins, minerals, carbohydrates,
fats, proteins,
and water) from foods and helps pass waste material out of the body.
The digestive system is made up of the esophagus, stomach,
and the small
and large
intestines. The first 6 feet of the large intestine are called the
large bowel
or colon. The last 6 inches are the rectum
and the anal canal. The anal canal ends at the anus
(the opening of the large intestine to the outside of the body).
|
|
 |
|
Anatomy of the lower digestive
system, showing the colon and other organs.
|
Age and
health history can affect the risk of developing colon cancer.
Risk
factors include the following:
- Age 50 or older.
- A family
history of cancer
of the colon
or rectum.
- A personal history of cancer of the
colon, rectum, ovary, endometrium,
or breast.
- A history of polyps
in the colon.
|
|
|
|
Polyps in the colon. Some
polyps have a stalk and others do not. Inset shows a photo
of a polyp with a stalk.
|
- A history of ulcerative colitis (ulcers in the lining of the large intestine) or
Crohn's
disease.
- Certain hereditary
conditions, such as familial
adenomatous polyposis and hereditary
nonpolyposis colon cancer (HNPCC; Lynch Syndrome).
Possible
signs of colon cancer include a change in bowel habits or blood in the
stool.
These and other symptoms
may be caused by colon
cancer or by other conditions. A doctor should be consulted if any
of the following problems occur:
- A change in bowel habits.
- Blood
(either bright red or very dark) in the stool.
- Diarrhea, constipation,
or feeling that the bowel does not empty completely.
- Stools that are narrower than usual.
- General abdominal
discomfort (frequent gas pains, bloating, fullness, or cramps).
- Weight loss with no known reason.
- Constant tiredness.
- Vomiting.
Tests that
examine the rectum, rectal tissue, and blood are used to detect (find)
and diagnose colon cancer.
The following tests and procedures may be used:
- Physical
exam and history: An exam of the body to check general signs
of health, including checking for signs of disease, such as lumps
or anything else that seems unusual. A history of the patient's
health habits and past illnesses and treatments will also be
taken.
- Fecal
occult blood test: A test to check stool (solid waste) for
blood that can only be seen with a microscope. Small samples of
stool are placed on special cards and returned to the doctor or
laboratory for testing.
|
|
|
|
Fecal Occult Blood Test (FOBT)
kit to check for blood in stool.
|
- Digital
rectal exam: An exam of the rectum. The doctor or nurse
inserts a lubricated, gloved finger into the rectum to feel for
lumps or abnormal
areas.
- Barium
enema: A series of x-rays
of the lower gastrointestinal
tract. A liquid that contains barium (a silver-white metallic
compound) is put into the rectum. The barium coats the lower
gastrointestinal tract and x-rays are taken. This procedure is
also called a lower GI series.
|
|
|
|
Barium enema procedure. The
patient lies on an x-ray table. Barium liquid is put into
the rectum and flows through the colon. X-rays are taken
to look for abnormal areas.
|
- Sigmoidoscopy:
A procedure to look inside the rectum and sigmoid (lower) colon
for polyps, abnormal areas, or cancer. A sigmoidoscope
(a thin, lighted tube) is inserted through the rectum into the
sigmoid colon. Polyps or tissue
samples may be taken for biopsy.
|
|
|
|
Sigmoidoscopy. A thin,
lighted tube is inserted through the anus and rectum and
into the lower part of the colon to look for abnormal
areas.
|
- Colonoscopy:
A procedure to look inside the rectum and colon for polyps,
abnormal areas, or cancer. A colonoscope
(a thin, lighted tube) is inserted through the rectum into the
colon. Polyps or tissue samples may be taken for biopsy.
|
|
|
|
Colonoscopy. A thin,
lighted tube is inserted through the anus and rectum and
into the colon to look for abnormal areas.
|
- Biopsy:
The removal of cells
or tissues so they can be viewed under a microscope to check for
signs of cancer.
- Virtual
colonoscopy: A procedure that uses a series of x-rays called computed
tomography to make a series of pictures of the colon. A
computer puts the pictures together to create detailed images that
may show polyps and anything else that seems unusual on the inside
surface of the colon. This test is also called colonography or CT
colonography.
Certain
factors affect prognosis (chance of recovery) and treatment options.
The prognosis
(chance of recovery) depends on the following:
- The stage
of the cancer (whether the cancer is in the inner lining of the
colon only, involves the whole colon, or has spread to other
places in the body).
- Whether the cancer has blocked or
created a hole in the colon.
- The blood levels of carcinoembryonic
antigen (CEA; a substance in the blood that may be increased
when cancer is present) before treatment begins.
- Whether the cancer has recurred.
- The patient's general health.
Treatment options depend on the following:
- Whether the cancer has recurred.
- The patient's general health.
Source Public Domain
The top six search requests for pages like this one
were:-
colon cleanse
colon cancer
colon cleansing
colon cancer symptom
colon cleanser
ultimate colon cleanse
