A cancer of the colon or rectum, which may begin as noncancerous polyps.

Colorectal cancer affects the colon or rectum, located at the lower end of the digestive tract.

Symptoms may vary depending on the cancer's size and location. Symptoms might include blood in the stool, abdominal discomfort, and a change in bowel habits, such as diarrhea or constipation.

Most colorectal cancers begin as noncancerous growths called polyps. Removing polyps can prevent cancer, so healthcare professionals recommend screenings for those at high risk or over the age of 45.