My wife sent me these pics of her starting to train her beautiful ass. She is just getting into it so she is taking it slowly, she can just get the head of that pink toy in. Hopefully we can get her trained up to the point of me putting my dick inside her.
There is more of a risk of injury during anal sex compared to vaginal sex.
http://en.wikipedia.org/wiki/Anal_sex
Just be careful with anal. I would suggest that a condom goes on anything going in ass...and don't go from ass and then to pussy or mouth...don't want an infection! Also, you can still transfer hpv and other stds even with a condom but it's less likely with one on.