Gastrointestinal imaging update: swallowing disorders and sphincter of Oddi dysfunction.

This update focuses on swallowing disorders and sphincter of Oddi dysfunction. Anatomy and physiology of swallowing are described, as are the signs, symptoms, and etiology of swallowing disorders. The imaging of these patients, particularly with videofluoroscopic swallowing study and fiberoptic endoscopic examination of swallowing, is then discussed. Sphincter of Oddi dysfunction as a cause of postcholecystectomy syndrome as well as its classification is described. This is followed by an explanation of the roles of fatty meal sonography and hepatobiliary scintigraphy in patients with sphincter of Oddi dysfunction, particularly type II and type III.