Anal sex....? Help!

Sorry this may be a bit TMI but i need some advice lately my partner really wants anal sex, but i keep saying no.

He doesnt know this but the reason I keep saying no is because i have tried it once with my previous partner (ex) and when he pulled out i had no control and heap of diarrhea came out.

I was so very horriblely embarrassed its really put me off ever doing it again.

I want to do it because i know that my partner wants to and i always want o try new things and explore our sex life but whats happen to me previously has embarrassed me for life!

Is there anyone else who has experienced diarrhea after anal,

Is there any tips?

Im scared that if i do decide to do it its going to happen again, and i really dont think i could deal with that 😬😑

Not to mention i think my partner would vomit then things would be really gross and messy 😂🙄

Can anyone help me out here ?

It was about 5yrs ago when i tried anal and never done it again since....