The small intestine is about 20 feet long. It is smaller in width, than the large intestine. There are different sections of the small intestines which are the duodenum, jejunum, and ileum. The lining of the small intestine contains thousands of microscopic glands. These microscopic glands release the intestinal digestive juice. The lining of the small intestine makes it especially well suited for the absorption of food and water.
The large intestine is about 5 feet in length. It is wider than the small intestine, hence its name. The large intestine forms the lower part of the digestive tract. Undigested and unabsorbed food material enters the large intestine after passing through the ileocecal valve. The ileocecal valve is what separates the small and large intestines.