Ultrasound in the diagnosis of sphincter of Oddi spasm.

Biliary colic from spasm of the sphincter of Oddi has been a difficult diagnosis to prove. We describe a patient in whom the diagnosis was arrived at using a pharmacological provocative test employing codeine to reproduce pain and a change in liver and pancreatic serum enzymes, and ultrasound to demonstrate a transient increase in common bile duct diameter. Testing carried out before surgical sphincteroplasty reproduced symptoms, and brought about marked pancreatic and liver enzyme elevation and an increase in common bile duct diameter measured by ultrasound (0.4 to 1.0 cm). Such events did not occur after sphincteroplasty. This case study suggests that codeine may be a useful provocative agent and that ultrasound measurements of changes in common bile duct diameter may provide a useful method in the diagnostic approach to Sphincter of Oddi Spasm.