Ask him to do a hemoccult (done in the office - doc sticks his finger up your a** and dabs it on a test material) or request a cologuard test (shit in a box at home and mail it to the lab! - loads of laughs driving cautiously to FEDEX!)

The hemoccult (FIT or FOBT) tests are <$100 and the cologuard ~$700. Your insurance will likely cover (esp. the hemoccult test) all the more if you tell doctor of your family background. Hemoccult tests were part of my routine annual physical for decades and there are no familial tendencies.

There are some caveats: e.g., avoid bloody foods in the days preceding these test (Chinese pigs' blood cubes, yummm!)