Surgery>>>>>Colon, Rectum, and Anus
Question 8#

A healthy 48-year-old physician with no family history of cancer and who strictly adheres to a high protein, high fiber diet, exercises five times per week for 50 minutes, and takes vitamin C supplements daily performs a fecal occult blood test (FOBT) on herself and tests positive. Should she have any further colon screening?

a. No, vitamin C can produce a false-positive result
b. Yes, all positive FOBT requires further investigation with a colonoscopy
c. Yes, all positive FOBT requires further investigation with FOBT in 1 year
d. No, she has no risk factors for colon cancer and should follow the USPSTF screening guidelines for colorectal cancer

Correct Answer is B


Fecal occult blood test (FOBT) has been a nonspecific test for peroxidase contained in hemoglobin; consequently, occult bleeding from any gastrointestinal source will produce a positive result. Similarly, many foods (red meat, some fruits and vegetables, and vitamin C) will produce a false-positive result. Any positive FOBT mandates further investigation, usually by colonoscopy.