Don't know how big you mean when you say big. I have a dildo that is a bit over 5.5 girth wise. It's only 7.0 long, and that is good enough for me. It takes me a while to get it all in, feels awesome when there. And yes, my ass returns to normal quickly afterwards.
Myself, I would not even contemplate going larger that it though. I have to work up to it from smaller ones, gradually. Nothing wrong with that, lots of play time.