What factors make you consider an EUS before embarking on an ERCP for concern for type 1 Sphincter of Oddi dysfunction, (appropriate biliary symptoms, dilatation of ducts with no stones on MRCP, and liver labs suggestive of cholestasis)?

When clinical presentation is not typical for SOD and imaging raises the question of an anatomical/structural cause, or history of idiopathic recurrent pancreatitis, a diagnostic EUS may be helpful in this context. If the clinical presentation with LFTs and imaging meets criteria for type 1 SOD, EUS...