1. Undigested waste is converted to faeces in colon and reaches rectum.
2. Faeces contain water, inorganic salts, sloughed of mucosal cells, bacteria and undigested food.
3. Distension of rectum stimulates pressure sensitive receptors that initiate a neural reflex for defecation or egestion.
4. It is a voluntary process that takes place through anal opening guarded by sphincter muscles.
