Large intestine absorbs some nutrients while also removing water and absorbs wastes. Colon which is the major portion of large intestine is responsible for absorbing water back into body.
The conversion of absorbed food in complex substances such as proteins and vitamins required by body is called assimilation.
After absorption from the food canal the digested food is assimilated by the body in the following ways:
Fatty acids and glycerol ate again converted into fats which are stored in the adipose tissue.
Sugar is converting into a complex polysaccharide, glycogen in the liver. This stored glycogen is metabolized and utilized during conditions of stress.
The amino acids absorbed from the intestine are utilized to synthesis various types of proteins in the body. The body needs to synthesis various proteins and various types of enzymes.
The excess amino acids cannot be stored by the body and needs to be deaminated in the liver and be converted into urea which is then removed from the blood by the kidneys and excreted.
The elimination of undigested remains of food from the alimentary canal is called egestion or defaecation. The waste material egested out from the anus is called faeces or stool.