EGESTION

1. To give out undigested food from alimentary canal.
2. Faeces can remain in colon for 36 hrs. then moving into rectum by gastro-colic reflex.
3. Faeces consists of 3/4 H O & 1/4 solid.
4. In solid part 3% bacteria, 30% roughage, 20% fat, 15% inorganic and 3% protein.
5. Dead mucosal cells, mucous, cholesteroal also present. NH₃, CH₄ are negligible.
6. Brown colour is due to stercobilin & Stercobilinogen.
7. Foul smell is due to sketol, Indol & treptophan.