The length of the duodenum is roughly the length of the twelfth finger. The main reason why it is called duodenum is that it is found that this section of the intestinal tube is roughly the length of the twelfth finger. In life, we often use our fingers to describe some lengths, roughly 1 finger width, 2 finger width or 3-5 finger length, so this section of intestinal tube was found to be the length of the twelfth finger during the procedure, and it is also called the duodenum. The length of the duodenum varies for each person, probably around 22-25cm, and generally this length is the length of the duodenum. Clinical diseases of the duodenum, often duodenal bulbar inflammation, duodenal descending smooth muscle tumor, duodenal cystic lesions, or in the duodenum of the papillary opening of the sphincter of Oddi enlarged, or the presence of duodenal diverticula.