At-Home Stool Test or Colonoscopy for Colon Cancer Screening?

I lost my aunt and grandfather to colon cancer. And I’ve had two friends die from colon cancer in their 50s — one left behind 4 children. So I didn’t hesitate to get a colonoscopy. I know it’s a lifesaving tool. But so, too, are at-home stool tests.  

These days, we have lots of options for colon cancer screening. Each has pros and cons, but there isn’t one single test that’s best for all people and situations, explains UVA Health colon cancer expert Cynthia Yoshida, MD. 

“The best colon cancer screening is the test that gets done,” she stresses. “They’re all great tests. They’ve all been documented to save lives from colorectal cancer.” 

Know Your Risk for Colon Cancer

Which colon cancer screening you use is a personal choice. But it’s important to consider whether you’re at average or high risk for colon cancer.

Because of my family history, colonoscopy was the right choice for me. But if you’re at average risk, you can choose any of the 5 tests available for colon cancer screening. And start by age 45.

So how do you decide? Read our quick guide below, where we break down your options and need-to-know details on each one.  

Guide to Colon Cancer Screening Options

If you need help, talk to your primary care provider about the screening best for you.

Colonoscopy

For years, colonoscopy was the main colorectal cancer screening option. And it’s effective — not only at finding cancer early. “If you are more interested in both detecting colorectal cancer and preventing cancer, then colonoscopy is really the way to go,” says Andrew Wolf, MD, a UVA Health primary care physician. He also chaired the American Cancer Society committee that developed colorectal cancer screening guidelines.

Colonoscopy screening is recommended for anyone with a high risk for colon cancer. This includes having:

• Family history of colorectal cancer
• History of inflammatory bowel disease
• Certain genetic syndromes 

How colonoscopy works: You’ll need to drink a liquid to clean out your colon and rectum the day before. On the day of the procedure, you’ll need to take time off work and have someone drive you home.

You’ll be given anesthesia to fall asleep. A doctor then inserts a scope with a camera to take a close look at your entire colon and rectum.

If they find polyps (abnormal growths that can turn into cancer), they can remove them during the same procedure. They’ll send any polyps to a lab for testing.

How often? If no polyps are found, you typically won’t need another colonoscopy for 10 years.

Flexible Sigmoidoscopy

This test is like a colonoscopy. But it only looks at the bottom 1/3 of your colon (sigmoid section). So a flexible sigmoidoscopy is not commonly used to screen for colon cancer. But it can be important in places where colonoscopy may not be available, Yoshida says.

At-Home Stool Test

It’s fascinating that our poop hides hidden clues about our health.

At-home stool tests are convenient if you’re at average risk for colon cancer:

• They’re easy to do in the privacy of your bathroom.
• Insurance covers the cost. You don’t pay postage for mailing.
• There’s no day-long prep needed like with a colonoscopy.

It’s best to get an at-home stool screening test with a doctor’s order. Many doctors’ offices stock them. But you can also get them mailed to your home. 

2 Options for Your At-Home Stool Test

There are 2 main types of at-home stool tests:

Fecal Immunochemical Test (FIT) 

This kit looks for hidden blood in the stool, which can be an early sign of colorectal cancer.

How it works: The kit includes everything you need, and the process takes just a few moments. When you’re ready to have a bowel movement:

• Place a piece of tissue over your toilet.
• Dip a wand into the passed stool.
• Seal the wand inside a tube.
• Mail it in for testing.

How often? Doctors recommend a FIT screening each year. 

FIT-Fecal DNA (Cologuard^®)

This stool test looks for more than blood in your stool. It also looks for altered DNA. Both blood and altered DNA can be early signs of colorectal cancer.  

How it works: Like a FIT test, you get a kit with everything you need. But instead of dipping the wand into the stool, you place a cup to catch your stool. You then mail in your sample for lab testing.  

How often? Doctors recommend repeating this test every 3 years.

CT Colonography  

Also known as virtual colonoscopy, this uses X-rays to create and examine a 3D image of your entire colon. While good at finding large polyps, this scan can miss small polyps. 

Wolf notes CT colonography is usually reserved for select patients like those who:

• Are at high risk for complications from colonoscopy
• Have narrowing that makes it difficult to pass a scope through the entire colon

How it works: Before the exam, you’ll need to clean out your colon by drinking a solution. You also may need to drink a contrast dye. This will make your colon easier to see during the virtual colonoscopy.

This test happens at an imaging center. You lie on a table and a scanner takes pictures of your colon. It takes less time than a colonoscopy. A bonus is that no sedation with anesthesia is needed.

How often? You’ll need to repeat this screening every 5 years if nothing is found. 

Positive Colon Cancer Screening? Next Steps

If your at-home stool test comes back from the lab with a positive result, or your CT colonography shows something concerning, you’ll need a colonoscopy.

Most of the time a colonoscopy doesn’t find cancer. Instead, it finds polyps that can be removed before they turn into colorectal cancer. This is what happened to me. And I no longer have to be scared of colon cancer. 

Start Screening by 45

For decades, colon cancer death rates have been declining among those older than 50, thanks to screening.  

But colon cancer is rising at alarming rates among those under 50. That’s why screening is a must-do once you reach 45. 

 And if you’re younger and have symptoms, don’t hesitate to talk to a doctor.  

Here’s a scary fact. We’re seeing an alarming increase in ‘early onset’ colon cancer between the ages of 20 and 49. And younger people are more likely to die from colorectal cancer. That’s because it’s not getting picked up at an early stage with screening, Yoshida says.  

DON’T ASSUME IT’S HEMORRHOIDS 

It’s important not to ignore symptoms of colorectal cancer:  

• Blood in your stools  
• Change in your bowel habits  
• Abdominal or back pain 
• Weight loss without trying 

Yoshida explains, “In the old days, if somebody complained about blood in their stools, your mother or your doctor would just say, ‘Oh, honey, it’s hemorrhoids. Don’t worry about it.’ But now, if you have symptoms, you really need to talk to your doctor about getting a colonoscopy.” 

She adds, “Colorectal cancer is not something that happens very rarely. We see this more and more in young people.”