This topic will tell you about the early testing, diagnosis, and treatment of colorectal cancer. If you want to learn about colorectal cancer that has come back or has spread, see the topic Colorectal Cancer, Metastatic or Recurrent. If you want to learn about anal cancer, see the topic Anal Cancer.
Colorectal cancer means that cells that aren't normal are growing in your colon or rectum . These cells grow together and form polyps. Over time, some polyps can turn into cancer.
This cancer is also called colon cancer or rectal cancer, depending on where the cancer is. It is the third most common cancer in the United States. And it occurs most often in people older than 50.
The exact cause of colorectal cancer is not known. Most cases begin as small growths, or polyps, inside the colon or rectum.
Colon polyps are very common. If they are found early, usually through routine screening tests, they can be removed before they turn into cancer.
Colorectal cancer usually doesn't cause symptoms until after it has started to spread. See your doctor if you have any of these symptoms:
- Pain in your belly
Blood in your stool or very dark stools
- A change in your bowel habits, such as more frequent stools or a feeling that your bowels are not emptying completely
If your doctor thinks that you may have this cancer, you will need a test, called a colonoscopy (say "koh-luh-NAW-skuh-pee"), that lets the doctor see the inside of your entire colon and rectum. During this test, your doctor will remove polyps or take tissue samples from any areas that don't look normal. The tissue will be looked at under a microscope to see if it contains cancer.
Sometimes another test, such as a sigmoidoscopy (say "sig-moy-DAW-skuh-pee"), is used to diagnose colorectal cancer.
Colorectal cancer is usually treated with surgery, chemotherapy, or radiation.