How is a digital rectal exam done to detect colon cancer?

Carefully: The physician will insert a gloved finger into the rectum, feeling for abnormal masses and or blood, stool should be tested immunologically for blood. Although still considered a screening evaluation that is acceptable, a colonoscopy is still the best screening tool we have for early colon/rectal cancer detection.

May not: A digital rectal examination can only test as far a finger will go into the rectum. A finger inserted through the anus cannot reach colon, therefore a digital rectal examination cannot detect colon cancer. However, rectum is part of the colon and a common site for cancer and a digital rectal exam is useful. Colonoscopy remains the gold standard for detecting colon cancer.