I'm sorry to hear that Bella might have a liver shunt...My Miko has a liver shunt, and he's doing fine now
This is an excellent site with info on liver shunts:
http://www.malteseonly.com/shunt2.html
Miko's liver shunt, unfortunately, is inoperable, so he is on medications and on a special diet for life now...He has responded very well to this, and the vet he should live for the most part, a normal life
Google liver shunts, and you will find a multitude of information on this topic...If you have any other questions, please don't hesitate to ask.