Everyone, thanks for responding. A second scan (a week apart) shows the ducts to be more dilated than they were. The surgeon is sending us to a GI doc for something called an ERCP. As I understand it, it's a scope they fish into the intestine to see what's causing the blockage. The doc said the best case scenario would be a stone, though he thought it highly unlikely (since my mom doesn't have a gall bladder). Nonetheless, I'm trying to remain calm (medicated, but calm). They will also take some cells from the intestinal tract and run tests. Of course my other concern is waiting 2 weeks for the ERCP given the noticeable difference in dilation within one week.