EBF and surgery?

I have to get my gallbladder taken out Wednesday they told me I can't feed him for 24 hours and to pump and dump but plenty of research online shows the anesthesia passes into the breast milk in low enough doses only for a few hours after that it's basically safe to feed once you wake up and can function? Has anyone had any experience with being put under and breastfeeding. I have plenty of milk saved up and plan on not feeding him for 12 hours after I wake up just to be on the safe side but just curious!