The intestine (also known colloquially as the gut) is a tube-like organ that starts at the base of the stomach and forms the longest part of the alimentary canal. Its function is to help with the processing of food. Humans have a large and small intestinal tract. The small intestine (which is actually by far the longer of the two) is made up of the duodenum and ileum. The large intestine is made up of the colon, caecum, appendix and rectum (or bowel).