You don't have to stop nursing at all.
I had one when my babes were only two months old. It was no big deal as far as the nursing. I had to use a saline laxative the night before, but that was fine while nursing. We did watch the babies for diarrhea but I was told it was a pretty low risk that it might bother them at all. Then I nursed right up until I left the house for the procedure.
I had Propofol during the procedure as a sedative http://www.eurekalert.org/pub_releas...-nmh031105.php
and the anesthesiologist recommended waiting about 6 hours afterward to nurse. I think many docs would recommend 24 but you will see in the above link that this does not seem to be necessary, and my doc even said the 6 hours was really probably not necessary. In the event, my DS was hysterical when I got home
so I nursed him right away, about an hour and a half after the procedure. He had no bad effects at all.
No big deal. And as far as me, I had no discomfort at all (except for the laxative, which wasn't nice) and the Propofol wore off quickly and didn't bother me at all afterwards.