The digestive system
lets the physician look
inside your entire large intestine, from the lowest part, the
rectum, all the way up through the colon to the lower end of the
The procedure is used to look for early signs of cancer in the
colon and rectum. It is also used to diagnose the causes of
unexplained changes in bowel habits.
Colonoscopy enables the physician to see inflamed tissue,
abnormal growths, ulcers, and bleeding.
For the procedure, you will lie on your left side on the
examining table. You will probably be given pain medication and a
mild sedative to keep you comfortable and to help you relax during
The physician will insert a long, flexible, lighted tube into
your rectum and slowly guide it into your colon. The tube is called
a colonoscope (koh-LON-oh-skope).
The scope transmits an image of the inside of the colon, so the
physician can carefully examine the lining of the colon. The scope
bends, so the physician can move it around the curves of your
You may be asked to change position occasionally to help the
physician move the scope. The scope also blows air into your colon,
which inflates the colon and helps the physician see better.
If anything abnormal is seen in your colon, like a polyp or
inflamed tissue, the physician can remove all or part of it using
tiny instruments passed through the scope.
That tissue (biopsy) is then sent to a lab for testing. If there
is bleeding in the colon, the physician can pass a laser, heater
probe, or electrical probe, or can inject special medicines through
the scope and use it to stop the bleeding.
Bleeding and puncture of the colon are possible complications of
colonoscopy. However, such complications are uncommon.
Colonoscopy takes 30 to 60 minutes. The sedative and pain
medicine should keep you from feeling much discomfort during the
exam. You will need to remain at the colonoscopy facility for 1 to 2
hours until the sedative wears off.
Your colon must be completely empty for the colonoscopy to be
thorough and safe. To prepare for the procedure you may have to
follow a liquid diet for 1 to 3 days beforehand.
A liquid diet means fat-free bouillon or broth, strained fruit
juice, water, plain coffee, plain tea, or diet soda. Gelatin or
popsicles in any color but red may also be eaten.
You will also take one of several types of laxatives the night
before the procedure. Also, you must arrange for someone to take you
home afterward-you will not be allowed to drive because of the
Your physician may give you other special instructions. Inform
your physician of any medical conditions or medications that you
take before the colonscopy.