This portion of the colon is lined Miracle Biotics and strong muscle tissues, which give the colon the necessary strength to expel waste into the rectum. The last portion of the large intestine is called the rectum. This is where waste materials are stored in the form of stool until they are excreted out from the anus. It consists of a thick mucosal lining and is supplied and many blood vessels. Now that we have understood the different parts of the large intestine, we can now move ahead to understand the function of each part. The digestion of food has already taken place in the small intestine, and only water and salt absorption takes place in the large intestine. Thus, the large intestine helps in maintaining the fluid balance of the blood. At the point of union of the ileum and the cecum, there exists a valve or sphincter muscle which opens and pushes food from the ileum into the expanding cecum.