Patient information: Flexible sigmoidoscopy

SIGMOIDOSCOPY OVERVIEW

A flexible sigmoidoscopy is an examination of the lower part of the gastrointestinal tract, called the colon or large intestine (figure 1). It is performed by an endoscopist, who is a doctor or other health professional with special training in endoscopic procedures. There are several reasons that flexible sigmoidoscopy may be recommended, with one of the most common reasons being the need to screen for colon cancer in people older than 50 years.

Colonoscopy allows the physician to examine the entire large intestine, and is preferred in certain situations. (See "Patient information: Colonoscopy".)

REASONS FOR SIGMOIDOSCOPY

The most common reasons for flexible sigmoidoscopy are the following:

• As a screening test to detect colon polyps or colon cancer (see "Patient information: Colon cancer screening")
• Blood in the stool or rectal bleeding
• Persistent diarrhea
• After radiation treatment to the pelvis when a patient has lower gastrointestinal symptoms
• Evaluation of the colon in conjunction with a barium enema
• For the medical management of colitis (inflammation of the colon)

SIGMOIDOSCOPY PREPARATION

A healthcare provider will provide specific Instructions about how to prepare for the examination. The instructions are designed to maximize your safety during and after the examination, minimize complications, and allow the endoscopist to easily view the colon.

It is important to read these instructions ahead of time and follow them carefully. Call your clinician or the endoscopy unit if you have questions.

Bowel cleaning — The lower part of the colon must be cleaned to permit the endoscopist to see the inside lining of the colon. You will be given specific instructions, with preparation usually including a clear liquid diet, laxatives, and use of an enemas shortly before the examination.

Medications — Some medications, such as aspirin products and iron preparations, should be stopped one to two weeks before the examination. Aspirin increases the risk of bleeding after the test, while iron coats the colon, making it difficult to see the lining. People who take a blood thinning medication such as warfarin (Coumadin®) should consult with their clinician regarding the need to stop taking this medication temporarily.

Most medications for high blood pressure, heart disease, lung disease, and seizure disorders are safe during sigmoidoscopy and can be taken the day of the examination.

Medications for diabetes may need to be adjusted before the test; talk to your healthcare provider for advice.

WHAT TO EXPECT DURING SIGMOIDOSCOPY

Prior to the sigmoidoscopy, a nurse will ask questions to be sure that you understand the procedure and the reason it is planned. A doctor will review the procedure, including possible complications, and will ask you to sign a consent form.

The procedure — Flexible sigmoidoscopy usually takes between five and fifteen minutes. It is performed while you lie on your left side with your legs curled up against your chest. The sigmoidoscope, which is approximately the size of one finger, is inserted into the anus and advanced through the rectum, sigmoid colon, and descending colon (figure 1). The sigmoidoscope has a camera and a light source that permits the endoscopist to look into the scope or at a television monitor.

The endoscope can be used to take biopsies (small pieces of tissue) and to introduce or withdraw fluid or air. Biopsies do not hurt because the lining of the colon does not sense pain. However, you may feel cramping as air is introduced through the scope and as the scope is passed through segments of the colon. The air is needed to permit the endoscopist to advance the scope and see the lining of the colon.

It is common to feel embarrassed about releasing air through your rectum, although this is recommended to decrease discomfort. Let the endoscopist know if there is discomfort since air can also be removed through the scope. Because the procedure is brief and discomfort is mild, pain medications or sedation are not routinely used.

SIGMOIDOSCOPY COMPLICATIONS

Flexible sigmoidoscopy is a safe procedure and complications are rare.

• Bleeding can occur from biopsies or the removal of polyps, but this is usually minimal and stops quickly or can be controlled.
• The scope can cause a tear or hole in the tissue being examined. This is a serious problem that does not occur commonly.

The following symptoms should be reported immediately:

• Severe abdominal pain (not just gas cramps)
• A firm, distended abdomen
• Vomiting
• Fever
• Bleeding greater than a few tablespoons

AFTER SIGMOIDOSCOPY

Although patients worry about discomforts of the examination, most people tolerate it very well and feel fine afterwards. Most patients are able to return to normal activities, including eating, after the examination

You should contact your doctor about the results of your test and if you have any questions. The endoscopy team will let you know when all the results will be available and if further treatment is necessary.

WHERE TO GET MORE INFORMATION

Your healthcare provider is the best source of information for questions and concerns related to your medical problem. Because no two people are exactly alike and recommendations can vary from one person to another, it is important to seek guidance from a provider who is familiar with your individual situation.

This discussion will be updated as needed every four months on our web site (www.uptodate.com/patients). Additional topics as well as selected discussions written for healthcare professionals are also available for those who would like more detailed information.

Some of the most pertinent include:

Patient Level Information:
Patient information: Colonoscopy
Patient information: Colon cancer screening

Professional Level Information:
Approach to the patient with colonic polyps
Colorectal cancer and primary sclerosing cholangitis
Colorectal cancer surveillance in inflammatory bowel disease
Evaluation of obscure gastrointestinal bleeding
Evaluation of occult gastrointestinal bleeding
Screening for colorectal cancer: Strategies in patients at average risk
Screening for colorectal cancer: Strategies in patients with possible increased risk due to family history

A number of web sites have information about medical problems and treatments, although it can be difficult to know which sites are reputable. Information provided by the National Institutes of Health, national medical societies and some other well-established organizations are often reliable sources of information, although the frequency with which they are updated is variable.

• National Library of Medicine

      (www.nlm.nih.gov/medlineplus/healthtopics.html)

• The American Society of Gastrointestinal Endoscopy:

      (www.askasge.org)

• National Digestive Disease Information Clearinghouse

      (http://digestive.niddk.nih.gov/ddiseases/pubs/sigmoidoscopy/index.htm)

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