The difference between the large intestine and small intestine mainly lies in the structural composition and function, as follows: 1. Structural composition: the human small intestine includes duodenum, jejunum and ileum, while the large intestine includes colon, cecum, appendix and rectum. 2. Function: the small intestine is relatively long and has a thin lumen, and is the main place for digestion and absorption after eating. Food through the esophagus, stomach to the duodenum, jejunum, ileum, food nutrients, such as sugar, fat, protein, vitamins and various minerals, in the small intestine by digestion, absorption, and then pushed into the large intestine through intestinal peristalsis. Compared with the small intestine, the large intestine has a thick lumen, but a short intestinal tube. The main function of the large intestine is to absorb the water from the food residue in the small intestine, then transport and store the feces formed, and finally expel it through the anus.