What Is a Sigmoidoscopy?
The colon helps your body absorb water
and nutrients from the food you eat. It’s also where your stool is formed. The
last third of your descending colon is called the sigmoid colon. It’s connected
to the anus by the rectum. A colonoscopy helps your doctor examine the entire
colon, but sometimes only the sigmoid colon warrants close inspection. That's
when your doctor will recommend a sigmoidoscopy.
A sigmoidoscopy, also called a “flexible
sigmoidoscopy,” is a procedure that lets your doctor look inside the sigmoid
colon by using a flexible tube with a light on it. It helps your doctor check
- abnormal cells
Typically, pieces of tissue will be
taken as samples to check for any abnormal cell changes.
When Is a Sigmoidoscopy Performed?
You should tell your doctor if you
- changes in your bowel habits
- rectal bleeding
- abdominal pain
- unexplained weight loss
These can be signs of various colon
diseases, and a sigmoidoscopy might be the procedure to help determine the
cause of your symptoms. A sigmoidoscopy is also a general screening tool for
Depending on your personal health
history and whether your family has a history of colorectal cancers, you might
need to have a sigmoidoscopy every five years after the age of 50.
Preparing for a Sigmoidoscopy
Preparing for a sigmoidoscopy is
similar to preparing for a colonoscopy. You’ll likely use one or more enemas
approximately two hours before the procedure.
If your entire colon needs to be
empty, you’ll need to prepare even more like you would for a colonoscopy. For
example, you’ll follow a clear liquid diet for one to three days before the
procedure. You may be given a powder laxative to mix with fluid to help empty
your intestines. Liquids you can consume include:
- plain coffee or tea
- fat-free broth
- gelatin, like Jell-O
- sports drinks with electrolytes
You’ll want to avoid liquid with red or
purple dye because it can look like blood in the colon.
Before the procedure, tell your doctor
about any medical conditions you have and all medications and supplements
What Does the Procedure Entail?
Your doctor will ask you to lie on
your left side on an examination table. They'll insert a thin, flexible tube
called a sigmoidoscope into your anus. The tube has a light and a very small
camera on the end so images can be transmitted onto a monitor for your doctor
to see. The tube will also inflate your colon with some air to make it easier
to examine. You might be uncomfortable, but the procedure isn’t typically
painful. Since you’re not usually under sedation during a sigmoidoscopy, your
doctor might ask you to shift every so often to make it easier to move the
If your doctor sees any polyps or
growths, they might remove them. If there are any abnormal areas in the colon,
small pieces of tissue might be removed for further examination.
are minimal, but it’s possible for a tear to occur in the colon or the wall of
the rectum on rare occasions. If your doctor takes a tissue sample, bleeding
could occur in the place where the sample was taken.
The entire procedure takes 10 to 20
minutes. People can usually drive themselves to and from the appointment. If
you’ve been given medication to calm or sedate you, you’ll need someone to
drive you home afterward.
What Can I Expect After the Procedure?
- severe abdominal pain
- bloody stool
Usually, some bloating or cramping is
normal after the procedure. Call your doctor immediately if you have:
- severe abdominal pain
- bloody stool
These can be signs of something
Your doctor will call you to discuss
the results of any biopsies. If there’s a positive result that requires further
testing, you may need to repeat the procedure. You may also need to repeat it
if your doctor wasn’t able to get a good quality picture of your colon and
rectum. Talk with your doctor about any questions or concerns regarding your
colorectal health or the results.