What is Colorectal Cancer?

Colorectal cancer is when abnormal cells grow together in the colon to form colon polyps or the rectum to form rectal polyps. These polyps can turn into cancer. It’s called colon or rectal cancer depending on where the polyp is located.

Colorectal cancer is the third most common cancer in the U.S.—the second leading cause of cancer-related deaths among men and the third leading cause for women. It occurs mostly in people older than 50.

An estimated 60 percent of colorectal cancer deaths could be prevented if people were screened routinely.

What are the causes of colorectal cancer?

Doctors don’t yet know the causes of colorectal cancer, or what causes a polyp to become cancerous. Colon polyps are common, but must to be found early to avoid turning into cancer.

What are the main colorectal cancer symptoms?

Symptoms of colorectal cancer are usually not evident until the cancer starts to spread. Symptoms include:

• Blood in stool or very dark stools
• Stools that are narrower than usual
• Change in bowel habits—more frequent or feeling that the bowels are not emptying completely
• Frequent gas pains or cramps
• Diarrhea or constipation

How is colorectal cancer screening done?

The American Cancer Society recommends regular colorectal cancer screenings for everyone age 50 and older. Doctors can use visual tests, stool-based tests, or both.

• Visual exams include:
• A colonoscopy every 10 years: This screening test involves using a thin, flexible tube with a camera on the end to allow the doctor to see the inside of the colon and rectum. A colonoscopy involves removing polyps and taking tissue samples of abnormal polyps.
• A flexible sigmoidoscopy every 5 years: This test is similar to a colonoscopy, but only covers the lower part of the colon.

• Stool-based tests include:
• A highly sensitive fecal immunochemical test (FIT) every year
• A highly sensitive guaiac-based fecal occult blood test (gFOBT) every year
• A multi-targeted stool DNA test (MT-sDNA) every 3 years

What is the treatment for colorectal cancer?

When colorectal cancer is caught early, the survival rate is 91 percent. Colorectal cancer treatment usually includes surgery, chemotherapy, or radiation.

More Information

Learn more about colorectal cancer screening by calling the American Cancer Society at or visiting their website .