Food moves through the GI tract by a process known as ‘Peristalsis’. The walls of the GI tract have muscles that push the liquid and solid and mix the content in the organs. The muscles behind the food squeeze and pushes the food forward whereas the muscles of the walls in front of the food relax allowing the passage of the food materials. The colon absorbs the water in the food and changes the food from the liquid form to a solid form called the stool. The last part of the digestive system is the rectum where the stool gets stored until it gets passed out of the body through the anus.