Colonoscopy
A colonoscopy is a procedure for viewing the interior lining of the large intestine
(colon) using a small camera called a colonoscope (which is a flexible fiber-optic tube).
Why a Colonoscopy is performed
A colonoscopy is generally recommended when the patient complains of rectal bleeding or
has a change in bowel habits and other unexplained abdominal symptoms. The test is
frequently used to test for colorectal cancer, especially when polyps or tumor-like
growths have been detected using the barium enema and other diagnostic tests. Polyps can
be removed through the colonoscope and samples of tissue (biopsies) can be taken to test
for the presence of cancerous cells.
The test also enables the physician to check for bowel diseases such as ulcerative
colitis and Crohn's disease. It is a necessary tool in monitoring patients who have a past
history of polyps or colon cancer.
How a Colonoscopy is performed
You lie on your left side with your knees drawn up toward the
abdomen. After administration of an intravenous sedative and analgesic, the instrument is
inserted through the anus and gently advanced under direct vision to the terminal small
bowel.
Air will be inserted through the scope to provide a better view. Suction may be used to
remove secretions.
Since better views are obtained during withdrawal than during insertion, a more careful
examination is done during withdrawal of the scope. Tissue samples may be taken with tiny
biopsy forceps inserted through the scope. Polyps can be removed with electrocautery
snares, and photographs can be taken.
Specialized procedures, such as laser therapy, can also be performed. |