What Is a Flexible Sigmoidoscopy?
A sigmoidoscopy is an internal exam of the lower part of the large intestine (colon) using a short, thin, flexible lighted tube.
The tube, called a flexible sigmoidoscope, has a tiny camera at the tip allowing the doctor to view the inside of the rectum and the sigmoid colon. Which is, the last two feet of the large intestine. Small biopsy instruments allow the doctor to remove tissue samples that he/she will check under a microscope. These samples are what doctors use to check for signs of disease and can be performed during the examination.
What is a Sigmoidoscopy Looking For?
A flexible sigmoidoscopy procedure can help your doctor determine the cause of abdominal pain, rectal bleeding, changes in bowel habits, chronic diarrhea and other intestinal problems.
Other things this a flexible sigmoidoscopy can detect include:
- Bowel obstruction
- Inflammatory bowel disease
- Anal fissures
- Colon polyps
Can a Sigmoidoscopy Detect Colon Cancer?
A sigmoidoscopy procedure does not allow the doctor to see the entire colon. Therefore, the doctor cannot detect any cancers or polyps farther into the colon with a flexible sigmoidoscopy. To examine the entire colon, a doctor may perform a colonoscopy to detect colon cancer.
Flexible Sigmoidoscopy Prep
Before the procedure, the lower colon and rectum must be completely empty for a flexible sigmoidoscopy to be thorough and safe. Some doctors recommend a combination of a laxative and a small enema before the test, as well as advising the patient to drink only clear liquids for 12 to 24 hours before the procedure.
A liquid diet means:
- Clear fluids, like water
- Fat-free bouillon or broth
- Strained fruit juice (no grape juice or any liquid with red color)
- Plain, unsweetened coffee or tea
- Diet soda.
The night before, or even immediately before the flexible sigmoidoscopy, the doctor may give the patient an enema, which is a liquid solution that washes out the lower intestine.
What Happens During a Flexible Sigmoidoscopy?
The entire sigmoidoscopy procedure lasts about 15 minutes. During the test the patient is laying on their left side with knees drawn up toward the chest.
- First, the doctor will do a digital rectal exam by gently inserting a gloved and lubricated finger into the rectum to check for any abnormalities.
- Next, the doctor inserts the sigmoidoscope into the rectum, and the patient will feel some pressure.
- Air is sent through the scope to expand the colon and help the doctor see adequately.
- As the scope is slowly removed, the lining of the bowel is carefully examined. A hollow channel in the center of the scope allows for the passage of an instrument called a forceps for obtaining a biopsy if needed.
What to Expect After a Sigmoidoscopy
After the exam, you may have mild abdominal discomfort such as bloating and/or passing gas for a few hours as you clear the air from your colon. This is normal. You will be able to return to your normal diet and routine after the procedure.
There may be a small amount of blood in your stool with your first bowel movement after the procedure. This is normal as well. Call your doctor if this continues or you have persistent abdominal pain or a fever of 100 degrees Fahrenheit or higher.
What Are the Possible Outcomes of a Flexible Sigmoidoscopy?
You and your doctor will discuss the results of your flexible sigmoidoscopy. The exam is negative if the doctor does not find any abnormalities. A positive exam might identify polyps or abnormal issue in the colon. Depending on the findings, you may need additional testing, such as a colonoscopy, so that the doctor can examine the entire colon.