Sphincter of Oddi Dysfunction

INTRODUCTION Sphincter of Oddi dysfunction (SOD) is a benign acalculous obstruction to the flow of biliopancreatic secretions through the sphincter of Oddi (1,2). In the general population, its prevalence is 1.5% (3). It is one of the known causes of post-cholecystectomy syndrome, and is observed in 14%–23% of these patients (4,5). The post-cholecystectomy syndrome can loosely be defined as a persistent or recurrent upper abdominal pain (usually right) following cholecystectomy and may be caused by gastroesophageal reflux, gastroparesis, or visceral hyperalgesia. Alternatively, retained common bile duct stones, which may be seen in 4%–7% of patients following cholecystectomy, or complications of the cholecystectomy including bile duct injuries and resultant bile leaks may be responsible for persistent post-cholecystectomy abdominal pain (6). However, if these causes are excluded and cholecystectomy was performed for only clinical biliary symptoms, SOD is the more likely cause for recurrent or persistent symptomatology. DISEASES OF THE BILLIARY TRACT, SERIES #2