Defecation (or defaecation) is the final act of digestion, by which organisms eliminate solid, semisolid, or liquid waste material from the digestive tract via the anus.

Humans expel feces with a frequency varying from a few times daily to a few times weekly. Waves of muscular contraction (known as peristalsis) in the walls of the colon move fecal matter through the digestive tract towards the rectum. Undigested food may also be expelled this way, in a process called egestion.

Open defecation, the practice of defecating outside without using a toilet of any kind, is still widespread in some developing countries.

 

Note:   The above text is excerpted from the Wikipedia article Defecation, which has been released under the GNU Free Documentation License.