Dear DumbNHIMF85,

The anus is the opening at the end of the rectum from which solid waste (feces) leaves the body — in both women and men. It's located right between the buttocks — behind the vagina in women and behind the testicles in men. Muscles inside and outside the anus, called "sphincters," open to let feces out or close to hold it in.

If a man ejaculates during unprotected anal sex, some of the ejaculate will be absorbed into his partner's body, but most of it will spill out the anus.

Like unprotected vaginal intercourse, unprotected anal intercourse is high-risk for many sexually transmitted infections, including HIV. Using condoms during anal sex decreases the risk of infection.

Hope this information helps!

Take care,

teenwire.com^® Editors

This column is for informational purposes only and is not intended to constitute medical advice, diagnosis, or treatment. If you have a medical problem, please call toll-free 1-800-230-PLAN for an appointment with the Planned Parenthood health center nearest you.