This supplies it with pancreatic juice from the exocrine pancreas, which aids in digestion.

Obstruction can also be due to duodenal inflammation in Crohn's disease.

[7] A gallstone may get lodged in the constricted distal end of the ampulla of Vater, where it blocks the flow of both bile and pancreatic juice into the duodenum.

[8] The pancreatic duct is generally regarded as abnormally enlarged if being over 3 mm in the head and 2 mm in the body or tail on CT scan.

[11] This is named after its discoverer, the German anatomist Johann Georg Wirsung (1589–1643).