sigmoidoscopy

Last reviewed 01/2018

Sigmoidoscopy is a procedure that is useful in rectal conditions. It precedes barium enemas if there is suspected rectal cancer.

The sigmoidoscope can be rigid or flexible. The flexible type gives better access. The rigid sigmoidoscope is a rigid steel or plastic hollow tube about 25-30 cm in length and 2 cm in diameter. It consists of an outer hollow tube, an obturator which is withdrawn after the instrument has been inserted, and a light source. There is a conduit for the insufflation of air to open up the bowel lumen ahead of the instrument.

Sigmoidoscopy can be used as a vehicle for biopsy of the rectum, for example in suspected ulcerative colitis, Crohn's disease and amyloidosis, or removal of polyps by snaring or diathermy.