Imagine a question and stream-of-consciousness explanation for which this is the answer: the final section of the small intestine
Question: The ileum / ˈɪliəm / is the final section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In fish, the divisions of the small intestine are not as clear and the terms posterior intestine or distal intestine may be used instead of ileum.

Where is the ileum located in the body?
Stream-of-consciousness: To answer the question, consider the following: The ileum / ˈɪliəm / is the final section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds.