Docs push you toward colonoscopies for good reason: Not only is it the most effective way to detect polyps, they can be removed right then and there if found. But, as you know, it requires a day of bowel prep (laxatives flush out everything to give your doc a clear view), and after the 30- to 60-minute procedure, some of the sedatives can take hours to wear off. (Unless you get it without sedation, as this guy did .)

So if youre one of the 33 percent of American adults not up-to-date on your screening, the best test is the one you actually get, says David Greenwald, M.D., director of clinical gastroenterology and endoscopy at Mount Sinai Hospital in New York City. Healthy guys need to start regular screenings at age 45, according to the American Cancer Society; people at higher risk , including those with a strong family history of colorectal cancer, should talk with their docs about how early to start.

All of these alternatives to colonoscopy come with a caveat: If any of them come back positive, youll still need a colonoscopy to remove polyps. So for a one-and-done approach, go for the colonoscopy. But these options can still give you some useful information:

FIT

The fecal immunochemical test detects traces of blood in your poop-once you smear said poop onto the card that comes in the box.

Pros: Buy the kits at the drugstore (about $15-$30, or get them from your doctor), do this test at home-it gives you the results within minutes. (Make sure it says FIT or Fecal Immunochemical Test; this is more accurate than the at-home Fecal Occult Blood Test.)

Cons : It can miss polyps and cancer, and you have to do it every year.

Best if : Theres zero way-even with all the gentle nagging in the world-that youre going to get yourself to the doctor for a colonoscopy.

FIT-fecal DNA (Cologuard)

Another at-home sample situation, this test detects traces of blood and also does a DNA analysis to see if abnormal cells that could indicate cancer have been shed into what you dump.

Pros: More accurate than the FIT.

Cons: Cologuard is better at finding cancer than polyps, explains Eduardo Vilar-Sanchez, M.D., associate professor, clinical cancer prevention, at MD Anderson Cancer Center in Houston. Why thats not good: You want to find and remove polyps before they turn into cancer. Plus, you cant buy this test direct. Your doc has to get you a prescription, and then you have to send your samples to a lab and wait for him or her to call you with results.

Best if: Youre willing to at least call a doctor to procure this for you.

Septin 9 Blood Test

This blood test was recently approved by the FDA-a lab can test your blood for markers of this cancer from the same blood draw thats used for your regular lab tests (cholesterol, for instance).

Pros : Nothing to smear, so theres a reduced ick factor

Cons : This is a big one: Its not that accurate. Some docs say that any test is better than none, but most arent rushing to give you this one.

A Higher-Tech Test, But Rarely Used

CT Colonography

A physician inflates your colon with air, then takes a CT scan of the pelvis and abdomen. The 3D images reveal polyps and other abnormalities.

Pros: Because theres no sedation, you can get back to the office once the test wraps.

Cons: You do need a prep, exposure to radiation is never great, and its possible to mistake specks of poop for polyps, leading to a false positive.

Best if: Your doctor wasnt able to perform a traditional colonoscopy due to twists and turns in your anatomy that roadblocked the scope (CT colonography usually isnt the first test offered).