What Are the Signs of Colon Cancer?

March is Colorectal Cancer Awareness Month.

The American Cancer Society estimates that 106,590 new cases of colon cancer will be diagnosed in the United States this year. Knowing the symptoms of colon cancer can help you protect your health.

While colon cancer remains common, the number of cancer cases has actually been decreasing over the last few decades. But colon cancer is increasingly being diagnosed in more advanced stages in younger adults than in the past.

That’s why it is so important to familiarize yourself with the potential signs of colon cancer and what’s normal for your body.

Defining Colon Cancer

Colon cancer is a type of cancer that originates in the colon, which is part of the large intestine. Colon cancer is often talked about together with rectal cancer under the name of “colorectal cancer.” 

In Texas alone this year, more than 12,000 people will be diagnosed with colorectal cancer. This type of cancer is often slow growing. Abnormal cells develop into growths called polyps, which form on the lining of the colon (or the rectum).

Polyps can take up to 15 years to develop into cancer, and they may never become cancerous. Because of that, polyps can often be removed before they even become cancerous.

Colon Cancer Symptoms

In many cases, colon cancer may not cause any noticeable symptoms, particularly in its earliest stages. As the cancer grows and spreads, though, it can cause a number of symptoms, including:

  • Bloody stool
  • Changes in bowel habits that last more than a few days
  • Diarrhea or constipation that doesn’t resolve quickly or recurs
  • Fatigue
  • Iron-deficiency anemia
  • Persistent bloating or a feeling of abdominal fullness
  • Stools in a thinner shape than usual
  • Weight loss with no known cause

Because these symptoms primarily relate to the digestive system, they can seem embarrassing or simply too personal to share. But it’s important to know what’s normal for you, bowel-wise, and to talk with a medical provider when you experience something out of your norm.

Why Colon Cancer Screenings Are Important

Colorectal cancer doesn’t always cause symptoms, especially in its earliest stages, when it’s most easily treatable. Colorectal cancer screenings provide an invaluable tool for detecting colon cancer or rectal cancer even before it causes symptoms.

When Should You Get Screened for Colon Cancer

The U.S. Preventive Services Task Force recommends that those at average risk of colorectal cancer begin screenings at age 45 and continue through at least age 75.

If you have risk factors that place you at a higher risk of developing colon or rectal cancer, such as a family history of the disease, your medical provider may recommend you begin screening earlier or have screenings more frequently. 

Take the colorectal cancer risk assessment on our health library.


There are multiple types of colorectal cancer screenings that are repeated at different intervals. A medical provider can help you determine which type of screening is best for your specific needs. Colonoscopy remains the gold standard for colorectal cancer screening because it is the only screening that scopes the entire colon and rectum and allows for the removal of polyps during the test.

That means that if precancerous polyps are discovered during a colonoscopy, the gastroenterologist performing the procedure can remove those polyps before they develop into cancer. If abnormalities are uncovered by other screenings, colonoscopy will be recommended as an additional diagnostic test.

Colon Screenings at University Health

Due for a colonoscopy or have digestive symptoms you’d like to have checked out? University Health providers are on your side. Schedule an appointment today.

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