What is colon cancer?

Colon cancer begins in the colon (large intestine). It’s sometimes referred to as colorectal cancer, which affects either the colon or rectum, another organ found in the lower portion of your digestive system. Many cases of colorectal cancer begin in the inner lining of one of the affected organs as a cancerous polyp.

Left untreated, colon cancer can spread from the inner lining of the colon to nearby lymph nodes or other parts of the body.

When colon cancer is in the early stages, many people don’t experience any symptoms. When symptoms do appear, they typically vary from person to person and are often dependent on the cancer’s size and location in the colon.

What are the symptoms of colon cancer?

People with colon cancer describe a range of signs and symptoms. Check with your doctor if you experience any of the following:

Risk factors for colon cancer

Colon cancer symptoms often don’t appear until after the cancer has grown or spread. That’s the reason many doctors recommend people predisposed to this disease be tested before symptoms become noticeable.

Risk factors for colon cancer include:

  • Age. Colon cancer can occur in younger people, but the great majority of those diagnosed are older than 50.
  • Racial/ethnic background. African-Americans have the highest colon cancer risk when compared to other racial groups in the United States. People of Ashkenazi Jewish descent have a higher risk of colon cancer compared to other ethnic groups in the world.
  • Inflammatory intestinal diseases. People who have a chronic inflammatory disease of the colon, such as ulcerative colitis or Crohn’s disease, are at a greater risk of colon cancer.
  • Type 2 diabetes. There is an increased risk of colon cancer for people with type 2 diabetes.
  • Family history of colon cancer. If you have a parent, brother, sister, or child of someone who has been diagnosed with colon cancer, you are more likely to develop it.
  • Personal history of colorectal polyps. People who have had many colorectal polyps in the past are at a higher risk of developing colon cancer.
  • Diet. Research has indicated that there is a link between colon cancer and a diet low in fiber and high in fat. According to the American Cancer Society, people whose diets are high in red meat and processed meat also have an increased risk for colon cancer.
  • Physical inactivity. People who aren’t active are more likely to develop colon cancer. Regular physical activity may reduce the risk.
  • Obesity. People who are obese have an increased risk of colon cancer.
  • Smoking. People who smoke tobacco products may have an increased colon cancer risk.
  • Alcohol. Heavy alcohol use increases the risk of colon cancer.
  • Genetic factors. Though rare, some inherited syndromes, such as Lynch syndrome and familial adenomatous polyposis (FAP), can increase the risk of colon cancer.

When to see a doctor

If you begin to experience pain or any irregular symptoms, schedule a visit to your doctor. Many colon cancer symptoms are similar to those caused by other health conditions, including:

Other symptoms may be caused by something less concerning. Certain foods — such as beetscan give your stools a black or red appearance that can falsely resemble blood. Even at the mildest indication, consulting with your doctor is still essential to receiving an accurate diagnosis.

When you’ve made an appointment to see your doctor, be prepared to provide complete information. Write down any symptoms you're experiencing, even those that might not seem related to colon cancer.

Also, be prepared to answer some questions about your symptoms, including:

  • When did you first begin experiencing these symptoms?
  • Have these symptoms been continuous or occasional?
  • How severe are your symptoms?
  • Does anything seem to improve these symptoms?
  • Does anything seem to make these symptoms worse?
  • Are you aware of any family members who’ve had history of colon cancer or other cancers?

What is the outlook for colon cancer?

Since many people don’t experience any symptoms at an early stage of colon cancer, doctors recommend people in high-risk groups get screened on a regular basis. People who do have symptoms associated with colon cancer should immediately make an appointment to see their doctor.

Don’t self-diagnose your condition. Many symptoms associated with colon cancer are indication of a more serious disease. Early detection can ensure you receive early treatment to alleviate your symptoms.