Acute Recurrent Pancreatitis and Dysfunction of the Sphincter of Oddi: Comparison between Invasive and Non-Invasive Techniques

The sphincter of Oddi (SO) is a structure consisting of smooth muscle fibers which surround the distal common bile duct, the main pancreatic duct and the ampulla of Vater. Its role is to regulate the flow of bile and pancreatic juices into the duodenum as well as to prevent the reflux of the duodenal contents into the pancreato-biliary system [1]. The abnormalities of SO contractility (sphincter of Oddi dysfunction: SOD) may be related to either the biliary or the pancreatic segments of the sphincter, or both [2]. On the basis of anatomic or functional abnormalities, two types of SOD have been postulated. SO stenosis is a chronic inflammatory proces