What is a flexible sigmoidoscopy?
A flexible sigmoidoscopy is a minimally invasive examination of the lining of the lower large intestine to evaluate gastrointestinal symptoms, such as abdominal pain, rectal bleeding, or changes in bowel habits. A sigmoidoscope is used and is a long, flexible, tubular instrument, in effect a smaller short version of a colonoscope. Use of a flexible sigmoidoscope for colon cancer/polyp screening used to be done frequently until the greater advantages of colonoscopy were understood, and now it is seldom done just for colon cancer screening in this country.
How do I prepare for my procedure?
To first prepare for your procedure make sure to talk to your physician about about any medical conditions you are prescribed and/or any over-the-counter medications, vitamins, and supplements you take, including:
- Arthritis medications
- Aspirin or medications that contain aspirin
- Blood thinners
- Diabetes medications
- Nonsteroidal anti-inflammatory drugs such as ibuprofen or naproxen
- Vitamins that contain iron or iron supplements
In addition, prior to your procedure, the rectum and the lower colon must be completely cleansed of stool. Your doctor will give you detailed instructions on how to cleanse your colon. In general, this requires the use of one or two enemas prior to the procedure and/or may also call for a laxative and some dietary modifications. This is done to obtain accurate results.
How is the procedure performed?
For the test, the person will lie on a table while the physician inserts a sigmoid scope into the anus and slowly guides it through the rectum (lowest portion of the colon) and into the sigmoid colon. The scope inflates the colon with air to give the physician a better view. The camera sends a video image of the intestinal lining to a computer screen, allowing the physician to examine the tissues lining the sigmoid colon and rectum. Once the scope has reached the furthest point that can be comfortably reached, the physician withdraws it slowly while examining the lining of the colon again but in more detail. Sometimes very small polyps are removed during the exam, or the biopsy instrument is used to obtain other tissue samples to assess growths or inflammation. This tissue is sent to the pathology lab for analysis. Depending what is seen, sometimes a complete colonoscopy or other testing might be advised. Using sedation for the procedure varies with the reason for the procedure and other factors that should be discussed with the doctor doing the procedure. Sedation is NOT normally needed.
What can I expect after my procedure?
After a flexible sigmoidoscopy, a person can expect to resume to regular activities and a normal diet. There may be slight abdominal cramps or bloating during the first hour after the test.
How long does the procedure take and where will it take place?
The visit for the sigmoidoscopy exam takes about 20 to 30 minutes but the procedure itself generally 5-10 minutes. A health care provider performs a flexible sigmoidoscopy during an office visit or at an ambulatory endoscopy center.
What are the risks involved with the procedure?
The risks of flexible sigmoidoscopy are very infrequent and ordinarily minor. These include
- Bleeding—rarely serious and mainly if large polyps are removed. Not all bleeding occurs immediately during the procedure; sometimes this can be delayed up to 10 days later.
- Perforation—a hole or tear in the lining of the colon. This is the most serious complication but is very unusual.
- Severe abdominal pain—ordinarily brief if it occurs, which is very infrequent.
- Feeling nausea, or faint, or having brief heart rhythm changes can occur with any endoscopy procedure, but is rare to be serious.
- The risks of complications occurring so severe as to be fatal would be extremely rare.
Any unexpected symptoms should be reported promptly to your physician.
What are my alternatives to this procedure?
Colonoscopy is a much more complete colon exam and is ordinarily preferred for screening the colon for polyps or cancer. An X-ray test (barium enema) or a CAT scan are alternative ways of looking at your large bowel. The main drawback of these tests is that they only provide pictures of the shape of your bowel, don’t show details of the interior lining and do not allow samples to be taken or for polyps to be removed. You would require a similar bowel preparation for these tests as well.