Sphincter of Oddi dysfunction (SOD) is a pathological syndrome that is usually classified into the biliary type or the pancreatic type according to the Milwaukee criteria. However, this classification has some drawbacks in clinical practice, some of which result in flawed classification and failure to properly guide diagnosis and treatment.
A research article published on January 21, 2011 in the World Journal of Gastroenterology addresses this question. The authors proposed a new classification system for SOD according to anatomy, symptoms, endoscope tests and radiological imaging, i.e. SOD is divided into four types instead of two types: the biliary-type, the pancreatic-type, the double-duct type and the biliary-pancreatic reflux type. The new classification demonstrates significant advantages for guiding the diagnosis and treatment of SOD patients in China, as compared with the conventional Milwaukee criteria.
Nonetheless, further investigations on the applicability of this quaternary classification system to patients in other regions are needed.