In this review, the function of the sphincter of Oddi (SO) is detailed in terms of normal motility, neural and hormonal control of SO function, coordination between gallbladder and SO motility, and correlation of motility of the SO and the duodenum. In addition, SO function tests, such as the morphine Prostigmin test (Nardi test), perfusion manometry, microtransducer manometry, and cholescintig...