Everybody loves to complain about getting a colonoscopy – how it’s a time suck and how emptying your colon is a pain in the, uh, neck – and then not get one. That’s scary when you consider that after lung cancer, colon cancer is the second-deadliest cancer in men. But that’s also why scientists are researching better methods to spot the disease.
Right now a number of screening options are available: stool-sample tests, a blood-sample test, even a virtual test. Tests you can do in the comfort of your own home also require the comfort to basically poop in a cup or on a piece of paper and deal with that sample yourself. Then there are tests that require sedation in a doctor’s office. Most people have no idea about the pros and cons of each or which are easier and/or more effective. Good thing we compiled all the info for you here.
Highest effort, highest accuracy: colonoscopy
Docs consider it the gold standard; patients gripe about the prep. Yet it’s still the best test we have – and plenty of people say, “It’s not that bad”.
What happens: You chug laxatives at home, then a doctor scopes your colon for polyps. If any are found, they can be removed and sent to a lab for analysis to determine if they’re cancerous, precancerous or noncancerous.
What’s to like: You get a screening, diagnosis, and removal all at once, says Dr Danielle Turgeon, a gastroenterologist specialising in colon cancer at University of Michigan Health. You need to do the procedure only every 10 years if you’re at average risk and nothing suspicious is found. (It’s every three to five years if you have polyps, and every one to three if you’re considered high risk.) Plus, if any alternative tests find polyps or suspect cancer, you must follow up with a colonoscopy, anyway. Another bonus: during the 30-60-minute procedure, you don’t have to do a damn thing – sedation is recommended – though you will need someone to drive you home afterwards.
What’s not to like: It requires some work – making the appointment, picking up the laxative prescription, staying close to the toilet to empty your colon, and doing a clear-liquid fast the day before and the day of the procedure. You’ll also need to take a full or half day off work to undergo the procedure and recover from sedation. People who don’t want to (or can’t) take time off sometimes opt for a no-sedation colonoscopy. It’s not for the faint of heart. Expect cramping-like discomfort – “similar to how diarrhea can be painful” – as the scope moves around your GI tract, says Turgeon.
The bottom line: “Colonoscopy has the highest sensitivity not just in detecting cancer but also in detecting polyps,” says Dr Ankit Sarin, a colorectal surgeon at the University of California, San Francisco. The test can detect cancer with 95 per cent accuracy.
Medium effort, good accuracy: multitarget stool dna testing (cologuard)
The second most accurate in detecting cancer after a colonoscopy, this test allows you to do the non-invasive stuff
at home.
What happens: You collect your poop and send it to a lab, which looks for blood and any DNA mutations associated with colon cancer or abnormal polyps.
What’s to like: No time off needed. Do it once and you’re good for three years.
What’s not to like: It’s still work. First, you need a prescription for a kit. Next, you aim your poop into the kit’s cup. But before you put the lid on and ship it off, you have to scrape a small sample into a vial. You then pour a preserving liquid into the main container, close it up and send both parts of the sample for testing within 24 hours. If results are positive, you’ll still need a colonoscopy. (Surprise!)
The bottom line: “It’s a great test for the person that has no risk factors for colon cancer,” Turgeon says. This type
of test is 92 per cent accurate in detecting cancer.
Low effort, okay accuracy: faecal immunochemical test (fit)
Collect a stool sample at home and send it off for testing.
What happens: You poop onto a piece of toilet liner, then scrape a stick over the deed to collect a grain of rice-sized sample. You’ll have to collect a second sample the next day before sending. Some kits, such as EZ Detect and Second Generation FIT, even let you test the stool sample immediately at home, with results delivered within five minutes.
What’s to like: The Australian government makes this one easy once you turn 50, sending you a free kit in the mail every two years until you’re 74 as part of the National Bowel Cancer Screening Program.
What’s not to like: Uh, scraping around in your poop? That’s too much for some.
The bottom line: FITs correctly identify people with colon cancer 74 per cent of the time, though the tests are not as good at detecting polyps as a colonoscopy or multitarget DNA test.
When to start screening
Right now
If a sibling was just diagnosed with colorectal cancer, get screened right away.
If you notice a change in bowel habits that lasts longer than a few days (narrow stools, diarrhea, constipation) or you see blood. You might get pushback from your doc about getting screened, but press for a test because, worryingly, discovery of colon cancer at a late stage is increasing.
Before age 45
If you have a personal or family history of colorectal cancer or polyps; a personal history of inflammatory bowel disease; or a hereditary colorectal cancer syndrome, such as Lynch syndrome.
If a parent or sibling had colon cancer, you should get your first screening 10 years before the age they were diagnosed, says Sarin.
At age 45
Anyone of average risk without any of the aforementioned risk factors, says Bowel Cancer Australia.
4 Other Tests
The key with prevention is to do something. Here are four other options to consider in your fight
to stay healthy.
Guaiac Fecal Occult Blood Test (gFOBT)
The gFOBT uses a chemical called guaiac to detect blood in the stool. The test isn’t as accurate as a FIT or multi-target DNA test and has a higher rate of false results. This test is most often used in limited-resource settings.
CT Colonography
This virtual colonoscopy takes CT images of your colon. It works, but accessibility may be an issue. It’s often conducted on patients who aren’t good candidates for a colonoscopy (anyone with severe cardiac disease).
Flexible Sigmoidoscopy
It scopes the lower third of your colon. Depending on where you live, a sigmoidoscopy might be more available than a colonoscopy, and it can be done without sedation, though it’s not as thorough. Docs typically combine it with a FIT.
Methylated septin 9 (mSEPT9)
In the US, this blood test is FDA approved for people 50 and older of average risk who have refused other screening methods, but it’s not as accurate as the other tests. Forget about it for now.
Illustration by quickhoney
