Rectum
DigestiveOrgansPelvis
- What it is
- Final segment of the large intestine, following the curve of the sacrum and widening below into the rectal ampulla; it has no haustra because the taeniae spread into a continuous muscle coat.
- Function
- Holds faeces before defecation; stretch receptors in its wall trigger the urge to defecate.
- Size
- About 12-15 cm long; the ampulla can widen to about 5 cm.
- Clinical note
- Three transverse rectal folds (Houston's valves) project into it; a finger in the rectum can feel the prostate or cervix through its front wall.