1. The third and final section of the small intestine, extending from the jejunum to the large intestine.
Usage: anatomy; medical

Examples

• The ileum is where most nutrient absorption occurs in the small intestine.
• Damage to the ileum can affect the body's ability to absorb vitamin B12.
• The ileum connects to the colon at a junction called the ileocecal valve.
• Crohn's disease often affects the ileum and other parts of the digestive tract.
• Surgeons sometimes need to remove a portion of the ileum in cases of severe intestinal disease.