Definition:
anal cancer (AY-nul KAN-ser)
Cancer that forms in tissues of the anus. The anus is the opening of the rectum (last part of the large intestine) to the outside of the body.
Enlarge Gastrointestinal (digestive) system anatomy; shows esophagus, liver, stomach, colon, small intestine, rectum, and anus.

Anatomy of the lower digestive system, showing the colon and other organs.