ANAL ISSUES

So I actually like anal, and last night wasn’t the first time I tried it. But it was the first time he didn’t use a condom for it. Today, I’m cramping slightly and (I know it’s TMI and gross) I have diarrhea. It’s it dangerous to let him cum inside my anal canal? I know it’s not very preventative towards pregnancy, but can it disrupt your bowel tract? I’m not trying to mess up my body!