But this test is invasive and expensive. Insurance may not pay for it. At home, you smear small samples on a card and mail it to a lab or doctor's office for analy-sis. This test will miss many precancerous polyps and some cancers, and it produces some false-positives. But it's still recommended by most authorities as a first step, and it has been shown to save lives.
Insurance covers it.
First, a barium enema is administered, and then the colon is inflated with air and X-rayed. It is useful but may miss smaller polyps. As a screening test, it is covered by insurance every 5 to 10 years for those 50 and older. Flexible sigmoidoscopy is an examination of the rectum and lower portion of the colon with a flexible, lighted tube. As a screening test, it is covered by insurance starting at age 50 and every five years thereafter, which is the recommended frequency.