Duodenum

The duodenum is the shortest and widest portion of the small intestine, which receives output from the stomach via the pylorus, and puts processed material into the jejunum.

Ulcers, often caused by Helicobacter pylori, are common in this area.

Increasing evidence is accumulating that the duodenum is the source of various hormones involved in hunger, obesity and other aspects of metabolism. This has been partially confirmed by the unexpected result of duodenal bypass bariatric surgery apparently curing Type II diabetes.