About Colon and Rectal Cancer

Colon cancers are cancers that form in the colon (the longest portion of the large intestine or large bowel), while rectal cancers form in the rectum (the last part of the large intestine). These cancers (also called colorectal or large bowel cancer) occur when cells in the body divide out of control, forming tumors.

Both men and women may be diagnosed with colon or rectal cancer. Colon and rectal cancer is the third most common cancer diagnosis in the U.S. (excluding non-melanoma skin cancers).

Risk Factors

There is no way to know for certain if you will develop colon or rectal cancer. However, a variety of factors may increase your risk for cancer of the colon and rectum, including if you:

  • Are over the age of 50. The risk of cancer of the colon and rectum increases with age.
  • Have a family history (a close relative including parents, brothers, sisters, or children) who has had colon or rectal cancer
  • Have had inflammatory bowel disease (IBD)
  • Smoke cigarettes

Symptoms of Colon and Rectal Cancer

The following can be symptoms of cancer of the colon and rectum. However, in their early stages, colon and rectal cancer and pre-cancerous colorectal polyps (or growths) may cause no symptoms. Screening tests can detect colon and rectal cancer at its earliest, most treatable stage. It is important to consult your doctor if you experience any of these symptoms:

  • A change in bowel habits, such as diarrhea or constipation, a feeling that your bowel is not emptying completely, or a narrowing of the stool
  • Rectal bleeding or finding blood in your stool
  • Feeling bloated or full
  • An enlarged abdomen
  • Feeling exhausted most of the time
  • Weight loss for no known reason
  • Nausea or vomiting