Colorectal Cancer Prevention: What You Need to Know

Colorectal cancer ranks fourth among the most common cancers as well as leading cause of cancer-related deaths in the U.S. While those statistics are alarming, the reassuring news is that early screening can help prevent it. As a Board Certified PA practicing in gastroenterology, I believe it’s important to share information on colorectal cancer symptoms and screening as early as possible.

What are the symptoms of colorectal cancer?

Precancerous polyps and even early colon cancers are often asymptomatic, making screening much more important. However, there are some symptoms that are concerning and should be evaluated by a medical provider, even if you are not due for screening. These symptoms include:

  • Change in bowel habits – This can be either diarrhea, constipation, or a sensation of not being able to empty completely.
  • Unintentional weight loss – The cause of weight loss in the absence of purposeful changes in physical activity or diet should be evaluated.
  • Blood present with bowel movements – No matter how small, blood in the stool should be evaluated by a medical professional to determine the cause. This includes blood that is constant and blood is seen intermittently.
  • Persistent abdominal pain – persistent abdominal pain, pressure, or discomfort is not only uncomfortable, but additionally warrants evaluation to determine a cause.

When should you get screened?

In 2021, The U.S. Preventive Services Task Force (USPSTF) recommended that asymptomatic adults of average risk start colon cancer screening at age 45 and continue to age 75. While pre-cancerous polyps and early colon cancer are typically asymptomatic, routine screening remains crucial.

It’s important to note that people who may not be considered “average risk” due to factors such as a personal or family history of colorectal cancer, history of adenomatous polyps, certain genetic disorders (such as lynch syndrome or familial adenomatous polyposis), or inflammatory bowel disease should speak about personalized screening with their PA or other medical provider.

What are the different screening modalities for colorectal cancer?

There are many screening modalities, each with advantages and disadvantages. It is best to speak with your medical provider to determine which method is right for you. Screening modalities for those at average risk include:

Stool Tests

  • Guaiac stool testing or fecal immunochemical test (FIT) – recommended every year.
  • FIT DNA testing (such as Cologuard) – recommended every three years.


  • CT colonography – recommended every five years.

Endoscopic Evaluation

  • Flexible sigmoidoscopy – recommended every five years.
  • Colonoscopy – recommended every 10 years.

An endoscopic evaluation is the only method able to both detect and remove polyps. While not all polyps turn into cancer, all colorectal cancer start as polyps. For this reason, if another form of testing was to be positive, a colonoscopy may be recommended for further evaluation. The frequency above is based on average risk, so for those with a history of polyps or other factors, screening may be recommended more often.

What else can you do to decrease your risk of developing colorectal cancer?

In addition to regular screening, lifestyle modifications, such as maintaining a healthy body weight, being physically active, consuming adequate dietary fiber, and limiting alcohol intake are all beneficial in colorectal cancer prevention. Start small; lifestyle modifications can feel daunting, but there are some easy-to-implement actions you can take, including:

  • Swapping an alcoholic beverage for water, 100% juice, or a mocktail.
  • Adding one extra fruit or vegetable a day to meals to help you feel full.
  • Swapping refined grains for whole grains, such as brown rice, whole wheat bread or pasta, quinoa, or oatmeal to increase your fiber.
  • Making it a habit to be more active, which could be taking a 15-minute walk at lunch, signing up for a fitness class, or lifting weights at home.

My overall advice: Act Now

The key to colorectal cancer prevention, detection, or successful treatment is to act now. It is never too early to start making lifestyle changes and discussing your personal and family history as well as screening options with your medical provider. They will help determine a plan that is right for you.




Picture of Cassidy McCandless MS, MPAS, RD, PA-C

Cassidy McCandless MS, MPAS, RD, PA-C

Cassidy McCandless is a Board Certified PA working in gastroenterology in Milwaukee, Wis., primarily serving patients with complex motility disorders. She graduated from Missouri State University in 2022, and prior to that worked as an outpatient Clinical Registered Dietitian. In 2022, she was awarded the AAPA PA Student of the Year Award and during school served as the PAEA Student Member at Large.