Gastroenterology Associates

of Central Pennsylvania, PC




Colonoscopy (koh-luh-NAH-skuh-pee)
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 small intestine.
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 exam.
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 colon. 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 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 endoscopy
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 sedatives. Your physician may give you other special instructions. Inform your
physician of any medical conditions or medications that you take before the colonscopy.

Printable colonoscopy instructions