Colonoscopy
A colonoscopy
is the visual examination of the large intestine (colon) using a
flexible fiberoptic or video endoscope. The colon begins in the
right-lower abdomen and then moves up and around the abdomen, ending
in the rectum. The colon is 5 to 6 feet long and has a number of
functions including withdrawing water from the liquid stool that
enters it so that a solid stool is produced.
Reasons
For a Colonoscopy
In the
colon, many types of problems can occur. The medical history, physical
exam, laboratory tests and x-rays can provide useful information
in making the diagnosis. The best examination of the colon can be
made through directly viewing the colon by colonoscopy. Colonoscopy
is used for:
- Diagnosing
cancer
- Polyps
- fleshy tumors which usually are the forerunners of colon cancer
- Colitis
- chronic inflammation of the colon
- Diverticulosis
and Diverticulitis - pockets along the intestinal wall
that develop over time
- Bleeding
lesions
- Abnormal
barium x-ray exam
- Chronic
diarrhea, constipation, or a change
in bowel habits
- Anemia
Preparation
To receive
the full benefits of the exam, the colon must be clean and free of
stool. The patient is instructed on how to do this. This process involves
drinking a solution which flushes the colon clean or taking laxatives
and enemas. Usually before the day of the exam, the patient only drinks
clear liquids and eats no food. The physician advises the patient
regarding the use of regular medications during that time.
Procedure
Colonoscopy
is usually performed on an outpatient basis. The patient is mildly
sedated, the endoscope is inserted through the anus and moved
gently through the bends in the colon. If a polyp is encountered,
a thin wire snare is used to lasso it. Electrocautery (electrical
heat) is then applied to painlessly remove it. Other tests including
a biopsy can be made by obtaining small tissue specimens for microscopic
analysis. The procedure takes 15 to 30 minutes and is seldom remembered
by the sedated patient. A recovery area is available to monitor vital
signs until the patient is fully awake. Mild cramping or abdominal
pressure following the exam is normal and within an hour this usually
ceases.
Results
After the
procedure, the physician and nurse will notate any significant findings
of the exam and inform the patient or family. If a biopsy has been
performed or a polyp removed, the results of these will not be for
14 days. The nurse and/or the physician will review all results of
the procedure at the post operative appointment approximately two
weeks after the procedure.
Benefits
of the Procedure
A colonoscopy
is performed to identify or correct a problem in the colon. The test
enables a diagnosis to be made and a specific treatment to be given.
If a polyp is found during the exam, it can be removed at that time,
eliminating the need for a major operation later. If a bleeding site
is identified, treatment can be administered to stop the bleeding.
Alternative
Treatments
Barium enemas
or other types of x-ray exams are alternative tests which outline
the colon and allow a diagnosis to be made. Study of the stools and
blood can provide indirect information about a colon condition. These
exams, however, do not allow direct viewing of the colon, removal
of polyps, or the completion of biopsies.
Side
Effects and Risks Bloating
and distension usually occur for about an hour after the exam until
the air is expelled. Serious risks are uncommon. One such risk is
excessive bleeding, especially with the removal of a large polyp.
Due to mild sedation, the patient should not drive or operate machinery
following the exam. For this reason, someone should be available to
drive the patient home.
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