My understanding has always been that colonoscopy is long proven to be one of the highest benefit ratio procedures in all of medicine. Let me see if there's a solid source for that... OK, here's the American College of Surgeons fact sheet - https://www.facs.org/~/media/files/education/patient%20ed/co...

Unambiguously stating that up to 90% of polyps or the tumors they grow into can be detected and removed. Also that lifetime risk of these cancers is 4.5%, versus a low risk of complications from the procedure. Compare to much lower detection rates for non-invasive procedures, and note that a positive from a FIT or FOBT will get you a referral for... a colonoscopy.

I don't have any expertise here, only marginal interest, and hoping like hell that it always stays that way. But it's not comforting to read that the odds of a serious horror show are higher than flipping a coin and getting heads 5 times in a row. Seems unlikely but do you want to bet your life on it?

Also not comforting to see the low rate of detection for the lab tests. FOBT misses 2 to 4 out of 10. FIT misses 97% of advanced cancer? That must be a typo. Checking... "FIT has been extensively evaluated for screening, with sensitivity estimates of a single low-threshold FIT for CRC approaching 90%." (https://gut.bmj.com/content/68/9/1642) But of course, that's once you have something that bleeds. The scope finds those earlier.

All very unnerving. A lot depends on the goal: catch your own cancer early, which suggests getting a scope early, or increase detection broadly among a population, which suggests focusing on easy-to-take tests that more people complete.