In order to answer your question accurately, there are two aspects to consider. The first is the safety of anal penetration itself, and the second is the safety of anal penetration with respect to the transmission of infection.
With regards to safety of anal penetration itself, there is no danger as long as you don’t try to force something too big into your anus or penetrate yourself with something sharp or breakable, or with something that you can’t retrieve from your anus. Some people are afraid that repeated penetration will cause the sphincter to loosen; this has not been shown to happen. Many women and men find anal stimulation to be a pleasurable sexual activity! The anus is a sensitive region rich with nerve endings that many people enjoy having stimulated in various ways, including orally, by touching or by inserting a finger, penis or sex toy. Many people enjoy the feeling of being penetrated anally. In addition, some men enjoy being penetrated because of the stimulation it can provide to the prostate gland.
Some people have negative associations with anal sex based on fears or negative or painful experiences. As with any sexual activity, feeling comfortable with what you are doing and being relaxed are important conditions for you to be able to enjoy it! You shouldn’t feel pressured into trying something you’re not comfortable with. If anal sex is something that you want to try, you can use a lubricant (water or silicon based) and your own finger to explore your anal region. This will help you familiarize yourself with feeling penetrated. The sphincter is made up of a series of muscles that are able to contract and relax. Taking time, breathing, exploring and learning to relax the muscles of the outer and inner sphincter will make it easier and more comfortable to be penetrated by a partner. Anal sex should not be painful. If you are experiencing pain or a burning sensation, you should stop, or take a break to relax and proceed more gradually. It is important to use plenty of lubricant when engaging in anal penetration since the anus does not lubricate itself. If you are having anal sex with a partner, it is equally important to proceed gradually. You can try starting with a finger or two before playing with anything bigger. Feel free to experiment with different positions and angles of penetration to find what is comfortable and pleasurable for you.
With respect to the transmission of infection, both unprotected anal and vaginal sex are high risk activities for the transmission of HIV (the virus that can cause AIDS) as well as other STIs. This is because both the vagina and the anus have fragile mucous membranes that can be irritated or torn by the friction experienced during sex, creating openings that allow the virus to enter your body if it’s in your partner’s semen. The best way to protect yourself is to use a condom and lubricant for both anal and vaginal sex.
If you are interested in more detailed information about anatomy, anal pleasure and penetration, there are books and videos available that provide more information on the subject. One such book that is pretty easy to find is Anal Pleasure and Health: A Guide for Men and Women by Jack Morin.
HIV Educator, ACCM