The process of digestion involves breaking down the contents of food eaten. It is broken down so that the body can absorb it to gain energy. There are many organs involved in digestion, and they include the stomach, small and large intestines, esophagus, and rectum. The process of excretion is when undigested food is removed from the body.
Like digestion, there are many organs involved in excretion, which include the kidneys, liver, bladder, and large intestine. Both of these processes are extremely important to the digestive system, which includes organs such as the liver, gallbladder, and GI tract. They are also both important to staying healthy.