(NSFW) Why and how do the nerves give pleasure (Details inside)?

I’ve read that the anus contains a greater concentration of ‘erotic’ nerve endings than any other body part.

Well there’s a revelation! Curious that so many of us are so fixated on areas less heavily wired.

Positive reinforcement. It is unhealthy to hold it in, so there has to be some encouragement to let it go.

Because full bowels do not feel good.

I think it’s the release and the ‘ahhhh’ relaxation that follows. Plus a high concentration of very sensitive nerves in that area.

Because you can’t help but feel relieved you didn’t poop in your pants.