What is the ileum?

It is called the ileum. Gray's Anatomy (1918) describes it as the final segment of the small intestine.

What it is

  • The final segment of the small intestine.
  • Thinner and narrower than the jejunum.
  • Absorbs vitamin B12, bile salts, and remaining nutrients.

Where it is

  • Between the jejunum and the cecum.
  • Occupies the lower right of the abdomen and the pelvis.
  • Joins the cecum at the ileocecal valve.

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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