V - we do something called a Sialogram in xray. The doc goes in, finds the duct and squirts some xray dye in there. He takes a look under fluoro (dynamic xray) and sees if there is a stone and if there is a stricture or other reason why it won't clear. Many times the stone gets dislodged and freed just from shooting in the dye. It is a way to find out why you are having this reoccur and it is painless. (but you do drool during it ) Just a thought...