Shit myself during anal sex. Now terrified to try again.

Hey Reddit.

I used to love anal. In fact, I know I would again if I'd let my boyfriend anywhere near there ever again. Last year, as he was pulling out, a tiny bit of poo came out with him. He didn't say anything, but I know he knows what happened. I'm so humiliated, I don't think I will ever get over it.

Since then, he's tried to entice me into trying again. I know he'd love to anally penetrate me again. However, I won't even let his finger anywhere near me.

My question for Reddit is- what can I do, hygiene wise, to ensure that this will NEVER, ever, happen? We're also experimenting with anal play with him as the recipient- how can he 'prepare' for more than my finger? Sometimes (sorry, gross), I can feel fecal matter up there? If I can't, I get really into it..but how can I communicate with him without saying 'I can feel shit in your ass'. I'd love to peg him..but I'm just so grossed out!

TL;DR Reddit, how do you enjoy anal play without the shit issue?

EDIT: I'm female. Forgot to add.