Individuals with sphincter of Oddi dysfunction present with abdominal pain resembling that of structural or inflammatory disorders of the gallbladder, biliary tree or pancreas.

[2] If all of the above criteria are met, individuals are classified as having a functional biliary sphincter of Oddi disorder, if the testing of pancreatic enzymes (amylase and lipase) is normal.

Type I included patients with biliary-type abdominal pain, with all of altered liver enzymes on blood testing, dilated biliary ducts on ultrasound or ERCP, and delayed bile clearance on HIDA scan.

The EPISOD trial has substantiated the ineffectiveness of endoscopic sphincterotomy in patients with these symptoms and SOD Type III is no longer considered to be a clinical entity.

In contrast, dyskinesia of the sphincter of Oddi is a purely functional disorder, wherein there is intermittent obstruction of the bile duct due to inappropriate spasms.

[5] Sphincter of Oddi dysfunction is best diagnosed using manometry-an internal test done to measure the pressures within surrounding ducts to determine whether or not the muscle is functioning normally.