July 21, 2021

How To Prevent Colorectal Cancer

Actions you can take today to lower your risk

colon cancer screenings

More than 130,000 people were diagnosed with colorectal cancer in 2020 — and that’s just in the United States. That’s a lot of people. What may surprise you even further is that colorectal cancer is actually preventable.


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“You can’t prevent breast, lung or brain cancer in the same way,” says colorectal surgeon David Liska, MD. “You can’t take precancerous polyps off any of those organs like you can with the large intestine.”

And the good news is there’s more to colorectal cancer prevention than the dreaded pre-colonoscopy bowel prep. Dr. Liska shares six ways you can lower your colorectal cancer risk — and keep your colon and rectum working just as they should.

What is colorectal cancer?

Colorectal cancer is a malignant tumor on the lining of the large intestine. It’s one of the leading causes of cancer-related deaths in the U.S. But it’s also highly treatable and curable when doctors find it early.

How to prevent colorectal cancer

Get regular screenings

“Colonoscopies save lives,” says Dr. Liska. Starting at age 45, everyone should get regular screenings with either a colonoscopy or one of the other recommended screening tests. That’s when colorectal cancer risk starts increasing.

When you’re high-risk: If colorectal cancer or advanced precancerous polyps run in your family, talk to your doctor about starting screenings earlier than what’s generally recommended. Colonoscopy math works like this: Take the age of the youngest affected relative when they were diagnosed with advanced precancerous polyps or cancer. Subtract 10 years from that age. That’s when you should start having colonoscopies and continue them every five years. So if your father had advanced precancerous polyps at 50, you would begin colonoscopies at age 40.

Benefits of a colonoscopy: “Every colon and rectal cancer arises from a precancerous polyp or other precancerous lesion, and it takes 10 years on average for a benign polyp to become cancerous,” explains Dr. Liska. “A colonoscopy allows doctors to find and remove colon polyps before they’re a problem.”


Regular colonoscopies prevent the majority of colorectal cancers. And, in fact, the rate of colorectal cancer diagnosed in patients over the age of 50 is decreasing in this country. It is encouraging to share that 65% of adults 50-75 are up to date on their screening. This decrease is largely due to screening and prevention by polypectomy. On the flip side, research shows that nearly all unscreened people know they should get a colonoscopy but still don’t.

“Sadly, every patient who walks into my office with colorectal cancer had a polyp that could have been removed,” Dr. Liska says. “They missed the boat for some reason or another: They were too scared, their family doctor didn’t recommend it, their insurance company wouldn’t pay for it or they had a colonoscopy, and their doctor didn’t see the polyp.”

A better colonoscopy experience: Colonoscopies have undergone a mini-makeover in recent years, with researchers working hard to improve the patient experience:

  • Prep “light.” Lower-volume options and split doses of osmotic laxatives (half the night before/half in the morning) are now available, making the prep more bearable.
  • Sweet dreams. While people may fear pain or inadequate sedation, 99% of patients are sedated enough (conscious sedation or twilight sleep) to be comfortable during their colonoscopy. Most don’t even remember it.
  • Fast, but not furious. They last 30 minutes, and then you’re done. Typically it takes 10 to 12 minutes to get the scope in comfortably and 12 minutes or so to take it out. That’s shorter than an episode of your favorite television sitcom. Full disclosure: It takes longer if doctors need to remove polyps, depending on the number and the size of them.
  • Safety first. Colonoscopies are safe. When performed by specially-trained professionals, the risk of perforation and bleeding is very low. “Get an experienced colonoscopist. Somebody who knows how to recognize polyps and remove them in the safest way possible,” Dr. Liska recommends.

Now that you’ve scheduled your colonoscopy appointment, what else can you do for colon health?

You are what you eat

To your honey-do list, add eating more fruits, vegetables, whole-grain breads and cereals, nuts and beans. They are linked to a lower risk of some cancers and can help you have healthy bowel function. Limit red meat and high-fat or processed meats, which can increase your colon cancer risk.

Be a weight watcher

Check your body mass index (BMI) regularly. Your risk of colon cancer increases if you have a BMI > 25 (have overweight) or a BMI > 30 (have obesity).


Sweat more

Do at least 30 minutes of moderate-intensity exercise five days a week. This will help you maintain a healthy weight and stay stress-free, which can decrease cancer risk. Examples of moderate-intensity exercise for a healthy adult include a brisk walk, gardening or doubles tennis.

Limit liquor

Keep an eye on your alcohol consumption, which is a general cancer risk factor. The recommended limits are one drink per day for women and two drinks per day for men.

Be a quitter

On top of many other health risks, smoking increases your risk of colon cancer, so take steps to quit right away.

It’s not every day we learn that cancer can be prevented. By taking the health-conscious steps above, you will lessen your chances of developing colorectal cancer.

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