A flexible sigmoidoscopy is an examination of the rectum and part of the large bowel using a device called a sigmoidoscope.

A sigmoidoscope is a long, thin, flexible tube attached to a very small camera and light source. It is the size of a finger in thickness and inserted into the back passage and up into the bowel.

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The camera relays images to a monitor, and can also be used to take biopsies, where a small tissue sample is removed for further analysis.

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During the test it is necessary to lie on the left side with your knees drawn up toward to the chest. As the flexible sigmoidoscope is pushed in to the bowel, air is gently pumped through the sigmoidoscope into the bowel to inflate slightly to help the doctor see the bowel wall more clearly. It might be necessary to change sides or lie on the back to help the camera through the bends in the bowel.

It is better for the lower bowel to be as empty as possible when sigmoidoscopy is performed, so an enema to flush the bowel clean is commonly used. It could be taken at home by oneself or given to you in the hospital. If taken at home it should be used at least two hours before leaving the house for the appointment. Sometimes the doctor ordering the test might prescribe strong oral laxatives to clean your bowel that you would need to take the day before your test.

A sigmoidoscopy can feel uncomfortable, but it only takes a ten to fifteen minutes. It is rare to require an injectable sedative or painkiller for the test.

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During the sigmoidoscopy samples (biopsies) will be taken if any abnormal areas are seen by the doctor. If any growths of the bowel lining (polyps) are seen they can be removed. All samples or polyps are sent to the laboratory to be looked at under a microscope.

Following the test, it is possible to go home straightway. Sometimes a small amount of bleeding from the back passage might occur after the sigmoidoscopy, particularly if polyps have been removed. This is normal and usually clears up on its own over a few days.