Colon Cancer. There are five common colon cancer tests: colonoscopy, virtual colonoscopy, sigmoidoscopy, barium enema, and stool testing. Each has benefits and drawbacks, so it's best to ask your doctor which colon cancer test is appropriate for you. In the meantime, however, here's an overview of the most common types of colon cancer tests. During a colonoscopy, a doctor inserts a flexible tube (called a colonoscope) into your anus.