Sphincter of Oddi dysfunction

Sphincter of Oddi dysfunction (SOD) is a benign non-tumoral disorder of the major papilla. It occurs mainly after cholecystectomy but can also occur before surgery. Biliary pain and biliary colic are the most frequent symptoms although recurrent pancreatic pain or pancreatitis can also be presenting symptoms. In about half of the cases, there is a fibrotic stricture of the sphincter of Oddi, probably secondary to the passage of biliary stones, while in the remaining half, the syndrome is due to ampullary motility disorders. The diagnosis of SOD first requires exclusion of choledocholithiasis or ampullary tumor, by means of ERCP, endoscopic ultrasound or magnetic resonance imaging. Findings on biliary manometry will establish the diagnosis, but this technique is performed less and less often because its high risk of inducing pancreatitis discourages its use as a diagnostic procedure. Biliary scintigraphy offers a risk-free alternative albeit with lower sensitivity. Medical treatment relies on the administration of trimebutine and nitroglycerine when pain occurs. Their efficacy is moderate. Sometimes patients are referred for endoscopic sphincterotomy. Endoscopic treatment should be performed only for patients with biliary pain associated with hepatic function disorders and/or bile duct dilatation. Practicians and patients should be aware that endoscopic sphincterotomy in this clinical setting is associated with a high risk of pancreatitis and its efficacy is limited in patients with pain but without laboratory anomalies or dilatation of the biliary duct (type III Milwaukee classification). Patients with Milwaukee classification type III disorders have mostly functional complaints or psychosocial disabilities and require only medical management.