Where it is
Central abdomen, from the pyloric sphincter to the ileocecal valve: duodenum, jejunum and ileum.
What it does
Receives bile and pancreatic enzymes in the duodenum and absorbs nutrients through villi. The terminal ileum absorbs vitamin B12 and bile salts.
Clinical relevance
- Crohn's disease often affects the terminal ileum and can cause B12 deficiency.
- Small bowel obstruction causes vomiting early; large bowel obstruction causes distension early.
Nursing focus
- An ileostomy produces liquid, enzyme-rich output: protect the skin and monitor fluid and electrolyte balance.