I wasn't sure where to post this?

After having anal sex with my boyfriend, I tend to get very gassy and it feels like I have to go #2. It's mostly gas except for some semen and a watery substance which I've read is "mucus discharge that the bowels will sometimes slough off after an anal invasion." It's kind of embarrassing and a little loud, and I would feel a little uncomfortable having to do it at his house (it usually doesn't happen until several hours after we have anal intercourse).

is there a way to prevent this from happening?

I could just tell him about it, I know he would understand, but it also causes some stomach pain from holding gas in.

any help would be appreciated, thanks.