The main job of the digestive system is to break down food (mouth, stomach and small intestine) so that other parts of the system (small intestine and large intestine) can absorb it. The system also excretes waste product (feces or poo) from food you have eaten. Aside from the mouth, stomach and intestines, the gall bladder and pancreas also secrete chemicals that aid in food digestion and absorption.
The main function of the digestive system is to break down food substances into a simpler and soluble form that can be absorbed by the body. When food is absorbed by the body it is used to nourish cells and provide energy.