Similar to a colonoscopy, a sigmoidoscopy is an examination of the colon using a flexible endoscope. Unlike colonoscopy, sigmoidoscopy only examines the rectum and lower part of the colon. The procedure may be a little uncomfortable but does not require sedation. Although biopsies can be taken, polyps cannot be removed.

Preparation for sigmoidoscopy involves taking two Fleets Ready-To-Use enemas two hours before the procedure.

Sigmoidoscopy may be used to evaluate rectal bleeding in young adult patients, to assess disease severity in inflammatory bowel diseases and under certain circumstances to investigate diarrhea. Sigmoidoscopy is sometimes performed for colon cancer screening and prevention, however, colonoscopy is generally recommended as a more comfortable, accurate and effective alternative.

Sigmoidoscopies are performed at the Endoscopy Center of Marin and Marin General Hospital.