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By Mayo Clinic staff
During the exam
During a flexible sigmoidoscopy exam, you'll wear a gown but likely nothing else. Sedation and pain medications usually aren't necessary.
You'll begin the exam lying on your side on the exam table, usually with your knees drawn toward your chest. The doctor will insert a sigmoidoscope into your rectum. The sigmoidoscope contains a light and a tube (channel) that allows the doctor to pump air into your colon. The air inflates the colon, which provides a better view of the lining of the colon. When the scope is moved or air is introduced, you may feel abdominal cramping or the urge to have a bowel movement.
The sigmoidoscope also contains a tiny video camera at its tip. The camera sends images to an external monitor so that the doctor can study the inside of your colon. The doctor can also insert instruments through the channel to take tissue samples (biopsies).
A flexible sigmoidoscopy exam typically takes about 15 minutes. It may require slightly more time if biopsies are taken.
After the exam
After the exam, you may have mild abdominal discomfort. You may feel bloated or pass gas for a few hours as you clear the air from your colon. Walking may help relieve any discomfort. You'll be able to return to your usual diet and activities right away.
You may also notice a small amount of blood with your first bowel movement after the exam. Usually this isn't cause for alarm. Consult your doctor if you continue to pass blood or blood clots or if you have persistent abdominal pain or a fever of 100 F (37.8 C) or higher.
- Corbett JV. Laboratory Tests and Diagnostic Procedures With Nursing Diagnoses. 7th ed. Upper Saddle River, N.J.: Pearson/Prentice Hall; 2008:743.
- Levin B, et al. Screening and surveillance for the early detection of colorectal cancer and adenomatous polyps, 2008: A joint guideline from the American Cancer Society, the US Multi-Society Task Force on Colorectal Cancer, and the American College of Radiology. Gastroenterology. 2008;134:1570.
- Colorectal cancer screening. Bloomington, Minn.: Institute for Clinical Systems Improvement. http://www.icsi.org/guidelines_and_more/gl_os_prot/preventive_health_maintenance/colorectal_cancer_screening/colorectal_cancer_screening_6.html. Accessed May 2, 2011.
- Flexible sigmoidoscopy. National Institute for Diabetes and Digestive and Kidney Diseases. http://digestive.niddk.nih.gov/ddiseases/pubs/sigmoidoscopy/index.htm. Accessed April 29, 2011.
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