USMLE Exam Prep

Answer - D - All three of these tests are considered standard screening tools for colorectal cancer. The most basic of these is the fecal “occult” blood test, which tests stool for the presence of hemoglobin from blood. Since colorectal tumors tend to bleed, if the stool has abnormal amounts of hemoglobin in it, a tumor could be a possible cause. A sigmoidoscopy or colonoscopy are procedures done by a physician to visually check for these tumors or other conditions utilizing a camera that is inserted into a patient’s rectum. A sigmoidoscopy does not go as far into the large intestine as a full colonoscopy does. As patients get older, the risk of colorectal cancer increases. Based on age and other risk factors, providers can determine which screening method is appropriate for their patients.