The digestive waste and unabsorbed substances in the ileum enter into the large intestine and it mostly contains fibre called roughage. The roughage is utilized by symbiotic bacteria in the large intestine for the production of substances like vitamin K and other metabolites. All these substances are absorbed in the colon along with water.
The waste is then solidified into fecal matter in the rectum. The fecal matter initiates a neural reflex causing an urge or desire for its removal. The egestion of feces through the anal opening is called defecation. It is a voluntary process and is carried out by a peristaltic movement.
