A colon with what appears to be a tumor

Colon Cancer

The term colon cancer is sometimes used interchangeably with colorectal cancer because colon and rectal cancers share common features. The rectum and colon make up the large intestine. Colorectal cancer is the fourth most common cancer in the United States, and it’s the second leading cause of cancer-related deaths.

Most colon cancers are caused by growths within the inner lining of the colon, called polyps. The chance of a polyp developing into cancer depends on factors, like the type of polyp (adenomatous polyps are considered precancerous) or if it has abnormal cells (called dysplasia).

Through routine screenings, most polyps can be found and removed before they turn into cancer. Screening tests include visual tests (colonoscopy) and at-home stool tests (fecal immunochemical test).

Frequently Asked Questions

  • What causes colon cancer?

    Most colon cancer develops from polyps with abnormal cells that start growing uncontrollably. There are several risk factors that increase a person's chance of developing colon cancer, such as leading a sedentary lifestyle, smoking, heavy alcohol intake, having a family history of colon cancer, or having an inflammatory bowel disease (IBD).

  • How do you prevent colon cancer?

    The most important step is to talk to your doctor about colon cancer screenings. Those considered average risk are encouraged to begin screenings at age 45.1 Lifestyle factors that may also be helpful include moderating your meat consumption, eating more produce and fiber, getting moderate to vigorous exercise, avoiding smoking, and limiting alcohol consumption.

  • What are the symptoms of colon cancer?

    Symptoms may not occur initially, but as the disease progresses, a person may notice a change in their bowel habits (persistent diarrhea or constipation) or dark or bright red blood in their stools. Other symptoms may include abdominal pain, cramping, weight loss, loss of appetite, or fatigue.

Key Terms

The Stages of Colon Cancer

Explore interactive models that show how colon cancer can metastasize (spread) in the large intestine, and how the disease changes as it progresses.

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Page Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. American Cancer Society. Can colorectal cancer be prevented? Updated June 9, 2020.

  2. National Cancer Institute. Cancer stat facts: cancer of any site.

  3. Anderloni A, Jovani M, Hassan C, Repici A. Advances, problems, and complications of polypectomy. Clin Exp Gastroenterol. 2014;7:285-96. doi:10.2147/CEG.S43084

Additional Reading