Anal, serious important question!

Okay... So, my boyfriend and I want to try anal at some point,  but, I'm really concerned about something. Please don't call me stupid if I'm really incorrect. I'm really afraid that, like, when he puts it in, he'll pull it out and there will be poop on him. Because when I wash, I obviously don't stick the soap inside my asshole and wash it out.. So if there was poop inside there, how would I get it out? Or does that not happen? Do girls always do an enema before participating in anal sex?
Please, only serious answers. Thank you!