Q. All  of the following statements accurately describe the limitations of sigmoidoscopy EXCEPT:

Only 40-50% of colon cancers are detected

Doing a sigmoidoscopy alone when screening for cancer is inadequate

In a person with 2 or more first degree relatives with colon Ca. It is important that colonoscopy be chosen

Occult bleeding in stool warrants a colonoscopy unless sigmoidoscopy shows hemorrhoids

The answer is 4. Occult bleeding in stool warrants a colonoscopy unless sigmoidoscopy shows hemorrhoids

Realize the limitations of sigmoidoscopic screening for colonic cancer

Explanation:

About 50-60% of the colon is missed as scope is only advanced to 60 cm in sigmoidoscopy.

In patients with occult bleeding or a family history of colon cancer (2 or more 1st degree relatives), a colonoscopy is warranted.