I don't know what the statistics are, but the percentage of people that enjoy recieving anal sex is rather large if it's "against nature". The percentage would be much larger if some people would just go with their nature.  Fear that God will be mad or that it makes you gay if you get pleasure "back there", keep many from even considering to try it.   I'm not going into the reasons why "god" doesn't want it (it's a form of birth control and god needs little soldiers to fight the heathens and convert them.) ( God, that created our Sun and everything else needs us to do this simple thing... kill non-believers, Ha!)

Let's see, anal sex does not ruin the sphincter, it's made to open and close.  There are far too many nerves in and around my anus just to let me know how well a turd slid out...  Yes dual function, like my pee hole, I pee and cum out of it.  Or a womans pee hole is between their vagina and clit.  Piss can be just as nasty as poop, yuck, and yet giving head and eating pussy both involve a peehole in your mouth. 

I'm not saying I like scat, I don't and I don't include it in sex, I clean first and she should too, but, if some shows up, I'm quick to get rid of it before continuing with the fun!

It's the perfect size and can open for any size cock. When I was a kid masturbating my ass, I used to worry that I was damaging myself (or would), but that never stopped me cuz the pleasure I got, and I always thought I would quit before that happened.  I'm 48 as I write this and my butthole still works fine, I started at 4, yes, 44 years of stuffing my butt.

Nowdays, and for the last 7-8 years I have really increased my anal masturbation, often times for hours a day, everyday!   I have to, cuz I get this craving and that's all I can think about, I make it a goal or a reward after getting things that need to be done, done.  Otherwise, I'd just fuck myself all day!  When I was a kid I remember thinking that when I grew up, I'd have a speciel room with all my toys and even a fucking machine so, I could enjoy anal for hours with no bothersome parents to hide from.  Well, I've done all that and it's GREAT!  However, it's better to have a friends cock in me, or piloting the dildo...  Whatever, I'm still very healthy and strong, it's not like smoking. That, is against nature.

I suppose this writing doen't fit with the title exactly, but what the hell. Anal sex (in spite of most strait men not having a clue how to give pleasure that way) is way too popular to not have a legitimate function in human sexuality.  The Creater made it that way, cuz He's a horny motherfucker too.:)