Thanx for all the thoughts and prayers! It really meant a lot!
quick update:
surgery took 12 hours and Isla is recovering. She is out for next day or two.
All did not go as well as we hoped for, but she is doing well and with a little bit of luck, she should be 100%. It could be years before we really know how well she adapts to the procedure. The worst case scenarios should be off the table though and even if things don't fully work out most likely side effects would barely be more than inconveniences.
Here's some info on the Hirschsprung's Disease:
http://en.wikipedia.org/wiki/Hirschsprung%27s_diseasepierre
