Crohn’s disease is a type of inflammatory bowel disease (IBD) that can affect any part of the gastrointestinal tract. Having either Crohn’s disease or another form of IBD is thought to increase the risk of cancer that starts in the colon.

Here’s what to know about the relationship between Crohn’s disease and colon cancer, how to lower risk, and the importance of screening.

According to the Crohn’s and Colitis Foundation, people living with IBD appear to have a notably increased risk of developing colorectal cancer, or colon cancer.

Longstanding inflammation in the colon is a likely culprit.

Crohn’s disease is a chronic inflammatory condition. It can affect the entire gastrointestinal tract, particularly the end of the small intestine or the colon. The cause of Crohn’s disease is unclear, but the gut microbiome may play a role.

Crohn’s disease is also considered to be an autoimmune disorder where the body mistakenly attacks healthy tissue. With Crohn’s, this can happen in the colon, leading to inflammation and an ongoing process of damage and repair on a cellular level. This continual repair and replacement of damaged cells raises the odds of errors in DNA that can lead to cancer.

According to a 2019 review, the strongest link between chronic inflammation and cancer is most apparent in colorectal cancer.

Research shows that people living with IBD are already at increased risk of developing colorectal cancer. Though the risk may not be as high for those who don’t experience inflammation in the colon.

Related risk factors include:

  • having ulcerative colitis or Crohn’s colitis (a form of Crohn’s that only affects the colon)
  • an 8-to-10-year history of Crohn’s disease or ulcerative colitis
  • severe or long-term inflammation of the colon
  • prior history of colorectal polyps or colorectal cancer
  • family history of colorectal cancer or adenomatous polyps
  • primary sclerosing cholangitis, a condition that causes inflammation and scarring of the bile ducts
  • dysplasia or precancerous cells found in the colon or rectum
  • inherited gene mutations like Lynch syndrome

According to the American Cancer Society, the risk of developing colorectal cancer rises with age, especially after age 50. African Americans have the highest colorectal cancer incidence and mortality rates of all racial groups in the United States. Ashkenazi Jews have one of the highest colorectal cancer risks of any ethnic group in the world.

Additional risk factors include:

  • having type 2 diabetes
  • being overweight or obese
  • being inactive
  • eating a diet high in red and processed meats
  • smoking
  • drinking alcohol

There’s no cure for Crohn’s disease, but there are ways to help control the underlying inflammation. See your doctor regularly to assess your health and adjust your treatment plan as needed.

Other ways to reduce risk include:

  • keeping a record of your symptoms and other concerns so you can discuss them with your doctor
  • taking your medications as prescribed, even if you’re feeling well
  • getting regular exercise
  • eating a nutritious diet and avoiding trigger foods
  • reaching and maintaining a healthy weight

It’s also a good idea to familiarize yourself with the signs and symptoms of colorectal cancer. These can include:

  • changes in bowel habits, such as constipation, diarrhea, or frequency
  • narrow or small stools
  • bright red or very dark blood in the stool
  • persistent abdominal or pelvic pain and bloating
  • nausea or vomiting
  • fatigue
  • unexplained weight loss

Let your doctor know if you experience any of these symptoms.

Most people with Crohn’s disease will never develop colon cancer. But due to the increased risk, it should be on your radar. The first step is to ask your doctor when you should be screened for colon cancer.

The U.S. Preventive Services Task Force (USPSTF) recommends colorectal cancer screening starting at age 45. Repeat screens should be done every 10 years. After age 76, the recommendation is for you and your doctor to weigh the potential risks and benefits of screening, though these guidelines apply to asymptomatic people at average risk.

If you’ve had symptoms of Crohn’s for 8 years or more, or have other factors that increase your risk of colon cancer, you should be screened every 1 or 2 years. Depending on your individual circumstances, your doctor may recommend more frequent screening.

Screening procedures

A colonoscopy is a test that’s used to screen for colon cancer. It allows the doctor to look inside the rectum and the entire length of the colon for any abnormalities or signs of cancer. If abnormal tissue is detected, the doctor may take a sample of the tissue for testing.

A colonoscopy can also detect precancerous polyps or lesions. These can be removed during the same procedure, which can prevent colon cancer from developing in the first place.

Some other tests used to screen for colon cancer are:

  • sigmoidoscopy, a procedure that allows the doctor to examine the inside of the rectum and lower colon
  • fecal occult blood test, which checks the stool for blood that can’t be seen
  • DNA stool test, which checks for genetic changes

Your doctor will recommend specific screening procedures and testing intervals based on your health history.


Early-stage colorectal cancer is highly treatable. Colon cancer doesn’t usually cause symptoms early on. Routine screening detect the cancer before symptoms develop. That’s why it’s important to stay on top of your screenings as scheduled.

Having Crohn’s disease or another type of IBD increases the risk of colon cancer. Work with your healthcare team on steps you can take to manage Crohn’s and lower your risk of colon cancer.

Speak with your doctor about when and how you should get screened for colon cancer. If you experience new gastrointestinal symptoms, see your doctor right away. Colon cancer is very treatable early on, which is why routine screening is so important.