Gastroenterology Associates

of Central Pennsylvania, PC


Flexible Sigmoidoscopy

Flexible sigmoidoscopy
(SIG-moy-DAH-skuh-pee) enables the
physician to look at the inside of the large
intestine from the rectum through the last
part of the colon, called the sigmoid or
descending colon. Physicians may use
the procedure to find the cause of
diarrhea, abdominal pain, or
constipation. They also use it to look for
early signs of cancer in the descending
colon and rectum. With flexible
sigmoidoscopy, the physician can see
bleeding, inflammation, abnormal
growths, and ulcers in the descending
colon and rectum. Flexible
sigmoidoscopy is not sufficient to detect
polyps or cancer in the ascending or
transverse colon (two-thirds of the

For the procedure, you will lie on your
left side on the examining table. The
physician will insert a short, flexible,
lighted tube into your rectum and slowly
guide it into your colon. The tube is
called a sigmoidoscope
(sig-MOY-duh-skope). The scope
transmits an image of the inside of the
rectum and colon, so the physician can
carefully examine the lining of these
organs. The scope also blows air into
these organs, which inflates them and
helps the physician see better.

If anything unusual is in your rectum or
colon, like a polyp or inflamed tissue, the

physician can remove a piece of it using instruments inserted into the scope. The physician
will send that piece of tissue (biopsy) to the lab for testing.

Bleeding and puncture of the colon are possible complications of sigmoidoscopy.
However, such complications are uncommon.

Flexible sigmoidoscopy takes 10 to 20 minutes. During the procedure, you might feel
pressure and slight cramping in your lower abdomen. You will feel better afterward when
the air leaves your colon.


The colon and rectum must be completely empty for flexible sigmoidoscopy to be thorough
and safe, so the physician will probably tell you to drink only clear liquids for 12 to 24
hours beforehand. A liquid diet means fat-free bouillon or broth, gelatin, strained fruit
juice, water, plain coffee, plain tea, or diet soda. The night before or right before the
procedure, you may also be given an enema, which is a liquid solution that washes out the
intestines. Your physician may give you other special instructions.