Feces also contains things like bile which was produced inside the liver and was used by the small intestine to basically emulsify break down our fat gloves into smaller fat molecules. And the feces also consist of those cells that were basically scraped off of the lining of our small and large intestines and other organs in our body such as our stomach. So at the bottom of the rectum we have the structure that is known as the anus. And the anus consists of two muscles of two sphincter muscles. One of those sphincter muscles known as the internal sphincter muscle is under involuntary control and that means the autonomic nervous system is responsible for opening and closing that internal sphincter muscle. Now the second sphincter muscle known as the external sphincter muscle is actually controlled voluntary.