Assimilation is a process by which the digested food is absorbed by the body cells become an integral component of their living protoplasm and is used for energy, growth and repair. For example, amino acids are assimilated by the formation of proteins that help in building body muscles, glucose is oxidised in the cells for the production of energy, etc.

The faecal matter is removed through the anus from time-to-time. This is called egestion. It also helps to remove any toxic substance that has entered into our body through oral route. In case of unicellular organisms like Amoeba , the waste materials are thrown of the body through the vacuole.

A typical problem associated with an upset stomach is indigestion. Bloating is frequently brought on by dietary changes, such as eating a lot of rich and fatty food. Stomach ache, discomfort, and gas are typical symptoms of bloating.