A flexible sigmoidoscopy is an examination of the left side of the bowel.

The doctor or nurse uses a flexible instrument called a sigmoidoscope. It is passed into the rectum (back passage) and up the left side of the large bowel. This area is called the sigmoid colon.

On the end of the instrument is a tiny camera that sends pictures to a video screen. Your doctor or nurse uses the pictures to look for anything unusual.

S/he may also take some small tissue samples (biopsies) from the bowel lining during the test. These will be sent to the laboratory to be looked at under a microscope.