Concomitant Sphincter of Oddi dysfunction type II and distal common bile duct stones: A coincidence or consequence?

Sphincter of Oddi dysfunction (SOD) is a rare condition characterized by impaired function or mechanical aberrancy of the sphincter. Diagnosis involves evaluating clinical symptoms, laboratory tests, and imaging findings. This article presents a case of SOD type II characterized by a lack of biliary dilatation in conjunction with distal common bile duct (CBD) stones during diagnostic investigations. A 73-year-old woman with previous cholecystectomy presented with severe, intermittent epigastric pain radiating to the right upper quadrant over two months. Laboratory studies were significant for persistently elevated liver enzymes. After a thorough workup that included imaging, autoimmune studies and liver biopsy, SOD type II diagnosis was suspected and an endoscopic retrograde cholangiopancreatography (ERCP) was performed with a sphincterotomy. Thereafter, the patient’s symptoms had abated. SOD is a complex clinical entity characterized by sphincter motility disorders that impede pancreatic or biliary fluid flow in the absence of structural abnormalities. Post-cholecystectomy SOD, affecting 1.5 % of patients, is more prevalent in women. Diagnosis involves excluding other pancreaticobiliary disorders through clinical evaluation, biochemical tests, and imaging. Management varies by subtype, with sphincterotomy showing efficacy in type I but less clear benefits in type II and III SOD. Challenges lie in the diagnosis and management of SOD type II due to overlapping symptoms and diagnostic limitations, necessitating further research to optimize therapeutic strategies and long-term outcomes.