A flexible sigmoidoscopy is a direct visual examination of the rectum, as well as a variable portion of the large bowel (colon). The procedure is usually carried out using a colonoscope, which is a thin, flexible tube about 11-13 mm in diameter with a camera and light source at its tip that displays a high definition image on a TV screen. Typically, patients are sedated for the procedure by a specialist anaesthetist.
When necessary, small tissue samples (biopsies) can be taken through a tiny channel within the colonoscope. Commonly a thin instrument is passed through the same channel to enable the removal of polyps (using a thin electric snare wire).
The procedure typically takes between 5 and 20 minutes.
