Papillary stenosis is a narrowing of the sphincter of Oddi, the muscular structure that surrounds the common bile duct and the pancreatic duct where they empty into the first part of the small intestine (duodenum).

This circular muscle constricts and relaxes to drain bile and pancreatic juices into the small intestine.

Typically, the sphincter relaxes after a meal to allow these digestive juices to mix with food. When the sphincter is unable to relax well, bile and pancreatic juice back up. This causes increased pressure in the duct systems that leads to pain. Pain typically occurs in the upper right or mid-abdomen.

Papillary stenosis is one cause of a "sphincter of Oddi dysfunction." Papillary stenosis may come from chronic scarring of the sphincter due to inflammation from passing small gallstones, surgical trauma or pancreatitis. The other and less well understood cause of sphincter of Oddi dysfunction is "biliary dyskinesia." These spasms of the sphincter occur as a result of hormonal or neurological influences, without any structural damage of the sphincter.

Sphincter of Oddi dysfunction most commonly occurs after the gallbladder is removed. The diagnosis hinges not only on how long and how severe the pain is, but also on tests that measure enzymes in the blood, imaging studies of the bile duct, and tests that measure the pressure within the sphincter.

Sphincter of Oddi dysfunction may be treated with drugs to relax the sphincter or with an endoscopic procedure (called a sphincterotomy) that cuts across and disrupts the sphincter.