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Rectal cancer vs. colon cancer: What’s the difference, and how can I cut my risk?

Doctors diagnose thousands of new colorectal cancer cases each year. Here’s how you can help prevent it.

If you just turned 45, your doctor may order a colon cancer screening test, such as a colonoscopy. That’s because 45 is the age when the U.S. Preventive Services Task Force suggests that people start getting regular colorectal cancer screenings.

Why are colorectal cancer screenings so important? Doctors diagnose about 150,000 new cases of colorectal cancer in the United States each year. It’s the second leading cause of cancer death, according to the American Cancer Society (ACS).

Is colon cancer the same as colorectal cancer?

The simple answer is no. “Colorectal” combines “colon” and “rectal,” which are different types of cancer that can form near each other in the body.

These cancers happen in a part of the body called the gastrointestinal (GI) tract, specifically the large intestine, which includes the colon and the rectum. But what they affect and how they behave, as well as how doctors treat them, are quite different, says Kyle Eldredge, D.O. He’s a colorectal surgeon in Wellington, Florida.

Here’s what you need to know about colon and rectal cancer, and what you can do to prevent them.

Need insurance that covers a colon cancer screening test? Find a plan online, or call a licensed insurance agent at 1-844-211-7730 to discuss your options.

What is the difference between colon cancer and rectal cancer?

The easiest way to think about the difference between colon cancer and rectal cancer is to know where each one occurs in the body:

  • Colon cancer occurs in the colon, otherwise known as the large intestine or large bowel.
  • Rectal cancer occurs in the rectum, the passageway that connects the colon to the anus. That’s sometimes called the anal canal.

“Your rectum makes up the last 12 to 15 centimeters of your large bowel,” explains Xavier Llor, M.D., Ph.D. He’s the director of the GI Cancer Prevention Program at Yale Cancer Center and Smilow Cancer Hospital.

Overall, rectal cancer affects less people than colon cancer, but rectal cancer is more frequent among younger people who develop colorectal cancer, notes Dr. Llor. Every year, doctors diagnose about 46,000 new cases of rectal cancer, compared with about 107,000 new cases of colon cancer, according to ACS.

How are colon cancer and rectal cancer similar?

They may affect different parts of the body, but colon cancer and rectal cancer have the same root cause. They stem from polyps, or abnormal growths, that form in either the colon or the rectum. Colon and rectal cancer also have similar symptoms. These include:

  • Changes in bowel movement (pooping) habits
  • Diarrhea, constipation or feeling like you can’t empty your bowels completely
  • Stomach pain or cramps that don’t go away
  • Unexplained weight loss

One exception is that you may see more red blood in your stool (poop) with rectal cancers, says Dr. Llor. But if you notice any of these symptoms, it’s a good idea to talk to your doctor.

Are the risk factors for colon cancer and rectal cancer similar?

Family history is the most important risk factor, but overall nutrition, body habits and environmental factors are behind most colorectal cancers, says Dr. Llor.

Both types of cancer can be caused by a genetic syndrome. That means they can be passed down from your parents to you. Some examples of genetic syndromes that could pass on colon or rectal cancer risk include familial adenomatous polyposis and Lynch syndrome.

But most of the time, you’ll be at a higher risk of colon or rectal cancer due to a combination of genetics, which you don’t have control over, and lifestyle factors, which you do have control over, explains Dr. Llor. These can include:

  • Eating a lot of red meat and processed meat (such as steak and deli meat)
  • Heavy alcohol consumption
  • Inflammatory bowel diseases such as Crohn’s disease and ulcerative colitis
  • Lack of exercise
  • Obesity
  • Smoking

Another thing you have control over? Having the right health insurance coverage. Get more details now about available plans, or call a licensed insurance agent at 1-844-211-7730 to discuss your options.

Do doctors treat colon cancer and rectal cancer differently?

If your doctor finds any polyps during a screening colonoscopy, they can remove them (and some cancers). Beyond that, your doctor may also have to surgically remove more of the colon cancer cells. If the cancer is large, a surgeon will perform a procedure known as a partial colectomy, where they remove the cancer and a small amount of surrounding healthy tissue.

If your surgeon can’t do that, they’ll make an opening, called a stoma, until your lower colon has healed. In rare cases, if the cancer is at an advanced stage, you may also need chemotherapy. That’s a type of cancer treatment that uses strong drugs to kill cancer cells.

Treatment for rectal cancer can be a bit different. Your doctor will not only remove the cancerous part of your rectum, but also all the fat and lymph nodes that surround it, explains Dr. Eldredge. (Lymph nodes are small structures inside your body that help filter out substances such as cancer cells.)

“Treatment for rectal cancer can include not only chemotherapy but also radiation, which we don’t do for colon cancer,” Dr. Eldredge says. (Radiation is a type of treatment that uses high doses of radiation to kill cancer cells and shrink tumors.) “The rectum has a lot of fat around it, so it’s easier for the cancer to spread to the lymph nodes. Radiation can help ensure that we shrink that tumor down.”

The reason for this? Rectal cancer can get into the sphincter muscle that helps you control your bowel movements. “We don’t want to have someone require a colostomy bag for the rest of their life,” stresses Dr. Eldredge.

How can I prevent colon cancer and rectal cancer?

The good news is that there’s plenty you can do to help reduce your risk of developing colorectal cancer, says Dr. Eldredge. A big one is staying on top of your screenings. There are a few different options, depending on what’s easiest and most comfortable for you:

  • At-home tests such as Cologuard. This looks for blood and other potential markers in your stool that can be linked to cancer. It’s recommended every 3 years.
  • At-home tests such as the Fecal Immunochemical Test (FIT). This checks for blood in your stool. It’s recommended once a year.
  • A colonoscopy. This is recommended every 10 years, or sooner if your doctor finds anything suspicious, such as a precancerous polyp.

While all 3 screening tests are good options, colonoscopies are the gold standard, says Dr. Eldredge. That’s because your doctor can also remove any polyps (and some cancers) if they discover them.

But if you are squeamish, a stool-based at-home test such as Cologuard or FIT is fine. “We know that any type of regular colorectal cancer screening reduces your risk of cancer by up to 70% or 80%,” says Dr. Eldredge.

These screening tests can also detect cancer earlier, when it’s easier to treat. Almost 88% of adults diagnosed with colon cancer or rectal cancer in the initial stages live for at least 5 years, compared with only 16% of those diagnosed with late-stage cancer.

Other things you can do to help prevent colorectal cancer include:

Eat the right food. Focus on a high-fiber, calcium-rich diet. Think foods like:

  • Fruits and vegetables
  • Low-fat dairy
  • Whole grains (such as oatmeal or brown rice)

Limit alcohol and red meat. Eating red meat and drinking alcohol are all right in moderation, but limiting them can lower the risk of colorectal cancer, according to a review of studies published in JAMA Network Open.

Stay active. Exercise has been shown to lower colorectal cancer risk. A recent study published in the British Journal of Sports Medicine found that exercise even lowers the risk of cancer recurrence in colorectal cancer survivors.

Get to a healthy weight. Research suggests that people who are obese are about 30% more likely to develop colorectal cancer, compared with people who aren’t. Talk to your doctor about ways to get to a weight that’s healthy and right for you.

Want a health insurance plan that covers screening tests like the ones listed above? Learn more about your options, or call a licensed insurance agent at 1-844-211-7730 to discuss them further.

Disclaimer: This article contains information that is not compiled by UnitedHealthcare or any of its subsidiaries. UnitedHealthcare does not represent all the information provided are statements of fact. Please consult directly with your primary care physician if you need medical advice.

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  1. American Cancer Society: “Key statistics for colorectal cancer.” January 13, 2023. Retrieved from
  2. British Journal of Sports Medicine. “Association between physical activity and the time course of cancer recurrence in stage III colon cancer.” March 6, 2023. Retrieved from
  3. Centers for Disease Control and Prevention. “Colorectal cancer screening tests.” February 23, 2023. Retrieved from
  4. Centers for Disease Control and Prevention: “What is colorectal cancer?” February 23, 2023. Retrieved from
  5. Centers for Disease Control and Prevention. “What should I know about screening? February 23, 2023. Retrieved from
  6. JAMA Network Open. “Role of diet in colorectal cancer incidence umbrella review of meta-analyses of prospective observational studies.” February 16, 2021. Retrieved from
  7. National Cancer Institute. “Colon cancer treatment (PDQ®)–patient version.” April 6, 2022. Retrieved from

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