Colon cancer screening offers a prime example of how acting in a preventive fashion can often be as tricky as providing treatment once a person is ill.

The situation came to my attention at the Mayo Clinic-backed Transform conference last month, where I learned that gastroenterologists and their patients now have another choice available when it comes to screening for colon cancer — the No. 2 cancer killer.

The colonoscopy remains the primary screening tool, but a new easier-to-deal-with alternative called Cologuard might gain favor over time and help to produce higher screening rates.

The major reason why? Cologuard doesn’t require the nasty preparation process of a typical colonoscopy.

cologuard-testkit-colon-cancerMy first thought was: What will gastroenterologists do with their time given they won’t be doing any more colonoscopies? Anyone who’s undergone the preparation for colonoscopy should understand why I would think people would avoid that prep if at all possible. Without getting too graphic, the Cologuard test sample is collected by the patient at home in a specially designed UPS shipping box (see photo). Sedation, days off from work and drinking laxatives are not necessary.

Since then, though, I’ve learned it’s a little more nuanced than that. GI specialist Shivan Mehta, M.D., speaking on behalf of the American Gastroenterological Association, explained why the available tests have pluses and minuses.

Reviewing the facts, it’s unclear to me what I would choose if I had to. The price of Cologuard seems a little steep at $500 every three years (that’s what Medicare pays). But colonoscopies can be performed just once every 10 years if no problems are found, albeit with the unpleasant prep, sedation and time away from work.

Yet, patients aren’t going to use it if they don’t know about it, and physicians have little incentive to prescribe Cologuard because they don’t get paid as they would for performing a colonoscopy. One would like to think that that wouldn’t come into play but doctors, like most people, care about how much they’re earning.

There also is an existing stool sample test that is a little less accurate than Cologuard, Mehta says, and it is recommended to be performed annually.

Perhaps Cologuard would be most useful for targeting patients who just won’t get a colonoscopy, but don’t want to get screened every year using the existing stool sample test.

Mehta, who also is associate chief innovation officer at Penn Medicine, noted that just two-thirds of adults get screened for colon cancer as recommended, adding that “the best test is the test that gets done.”