Health Encyclopedia

Sigmoidoscopy

Definition

Sigmoidoscopy is an internal examination of the lower large bowel (colon), using an instrument called a sigmoidoscope. The sigmoidoscope is a small camera attached to a flexible tube. It is inserted into the colon to examine the rectum, and the sigmoid and descending portions of the colon.

Alternative Names

Proctoscopy; Proctosigmoidoscopy

How the test is performed

During the test, you wear a hospital gown so that the lower half of your body is exposed. You are positioned on your left side with your knees drawn up toward your chest.

A gastroenterologist (a specialist in diseases of the digestive system) will gently insert a gloved and lubricated finger (or fingers) into the rectum to check for blockage and to dilate the anus. This is called a digital rectal examination.

Following the digital rectal exam, the sigmoidoscope will be inserted. This flexible fiberoptic tube is about 20 inches long.

The scope is gently advanced into the colon. Air is introduced into the scope to aid in viewing. The air may cause the urge to defecate. As the sigmoidoscope is slowly removed, the lining of the bowel is carefully examined. A channel in the scope allows for the passage of forceps for biopsies or other instruments for therapy.

How to prepare for the test

You must sign an informed consent form. You will wear a hospital gown.

On the morning of the procedure, eat a light breakfast and then use a cleansing enema about 1 hour before the sigmoidoscopy.

Infants and children:

The preparation you can provide for this test depends on your child's age, previous experiences, and level of trust. For general information regarding how you can prepare your child, see the following topics:

Infant test or procedure preparation (birth to 1 year)
Toddler test or procedure preparation (1 to 3 years)
Preschooler test or procedure preparation (3 to 6 years)
Schoolage test or procedure preparation (6 to 12 years)
Adolescent test or procedure preparation (12 to 18 years)

How the test will feel

There will be pressure when the scopes or fingers are introduced into your rectum. There will be a feeling of the need to defecate during the procedure. There may be some bloating or cramping from distention of the bowel by air or stretching by the sigmoidoscope. Biopsies cause no discomfort.

After the test, you will expel the air that was introduced.

Why the test is performed

This test can help diagnose:

Inflammatory bowel disease
Bowel obstruction
Colon cancer
Colon polyps
Diverticulosis (the presence of abnormal pouches on the lining of the intestines)
Causes of diarrhea
Causes of abdominal pain

This test can also be used to:

Determine the cause of blood, mucus, or pus in the stool
Confirm findings of another test or x-rays
Take a biopsy of a growth

Normal Values

Normal findings show that the lining of the sigmoid colon, rectal mucosa, rectum, and anus appear normal in color, texture, and size.

What abnormal results mean

Abnormal results can indicate:

Hemorrhoids
Anal fissures
Anorectal abscess
Cancer
Colorectal polyps
Inflammation or infection (proctitis)
Bowel obstruction
Inflammatory bowel disease
Diverticulosis

What the risks are

There is slight risk of bowel perforation (hole) and bleeding at the biopsy sites (the overall risk is approximately 1 out of 1,000).

Review Date:5/8/2006
Reviewed By:Jenifer K. Lehrer, MD, Department of Gastroenterology, Frankford-Torresdale Hospital, Jefferson Health System, Philadelphia, PA. Review provided by VeriMed Healthcare Network.

ADAM Quality A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is the first of its kind, requiring compliance with 53 standards of quality and accountability, verified by independent audit. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial process. A.D.A.M. is also a founding member of Hi-Ethics (www.hiethics.com) and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).

The Agency for Health Care Administration (Agency) and this website do not claim the information on, or referred to by, this site is error free. This site may include links to websites of other government agencies or private groups. Our Agency and this website do not control such sites and are not responsible for their content. Reference to or links to any other group, product, service, or information does not mean our Agency or this website approves of that group, product, service, or information.

Additionally, while health information provided through this website may be a valuable resource for the public, it is not designed to offer medical advice. Talk with your doctor about medical care questions you may have.