The advice I give to BFing women prior to surgery (and I make a lot of "be here at x time and fast from y time" calls as part of one of my nursing jobs) is to chat to the anesthetic team about exactly when they need to stop clear fluids. Some will extend the time for BFing women (but this depends on the anesthetist, the type of anesthetic they plan to use, your medical history, and their personal preferences over these things). So have a chat to them about it about a week before (or sooner).

In regards to pump and dump, none of the anesthetists I work with recommend that to patients. And they all make sure the patient receives extra IV fluids (unless there is a specific reason why they can't have extra fluids such as certain heart conditions) even if it is a short procedure.

HTH

MG