What is the anus?

It is called the anus. Gray's Anatomy (1918) describes it as the external opening of the digestive tract.

What it is

  • The external opening of the digestive tract.
  • Surrounded by two muscular sphincters — an internal (smooth muscle) and an external (voluntary).
  • Controls the release of feces.

Where it is

  • At the lower end of the anal canal.
  • Between the buttocks.
  • The perianal skin is richly supplied with sensory nerves.

Source:

Last verified: 2026-07-18

  • Best Anatomy Answers is an educational reference about human anatomy. It is not medical advice — for any health concern, talk to a licensed medical professional.

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