Since its introduction to much of mainstream culture in the 1972 film Last Tango in Paris, anal sex has usually been portrayed as deviant and abnormal, but its movement toward the norm persists.
"Some people like [anal] because it seems taboo or naughty," said Jack Morin, sex therapist and author of Anal Pleasure and Health. "Some people like the flavor of dominance and submission ... some don't."
For some homosexual men, anal sex is less unusual.
"It's our version of intercourse," said 22-year-old Chad T. "It's about the emotional connection."
He added that though it feels good, he's not a big fan because of the complex logistics and preparation involved.
There are physical reasons, too, that make anal sex different (and more appealing to some people) than vaginal sex.
Men have prostate glands located at the front wall of the rectum. When pressure is applied to these glands, as with anal penetration, the sensation is pleasing, Morin said.
"It's anatomy; whatever is in there, when you stimulate it, it feels good," Chad said. "Every man has it, gay or straight."
Multitudes of nerve endings surround the rectum in both men and women, so stimulation of the anus can produce greater sensation than that of other erogenous zones.
According to a U.S. Department of Health study of the sexual behavior of people between the ages of 15 and 44, "40 percent of men and 35 percent of women have had anal sex with an opposite-sex partner."
Just like all other sexual activities, anal sex brings with it important health issues that one needs to address before partaking. Some feel giving anal sex is not as risky as receiving it, and while this is true to some extent, the penis can absorb fluid and blood, said Robert Marks, Disease Intervention Specialist Supervisor for King County.
"Anal sex is regular sex," Marks said. "It is important to have conversations with your partner about HIV/AIDS status and when he or she was last tested."
Anal sex can be painful if you don't allow your body to prepare for it, Morin said.
"Much like people hold stress in their necks and shoulders, a lot of people hold stress in their anus," said Morin.
He suggested that the best way to prepare is to work on loosening the muscles that surround the anus. If these muscles are too tight, the experience can be very painful, but once they are relaxed, many people say they like the snug, filling sensation of penetration.
Unlike the vagina, the anus does not have a natural lubricant that builds up during arousal, so a good synthetic alternative is crucial. Morin suggests oil-based lubricants because they are thicker and last longer than other lubricants, but water-based lubes are easier to clean up.
It's important to keep in mind that oil-based lubricants compromise the integrity of latex condoms, decreasing their protective efficacy.
Additionally, the rectum should be kept clean. Morin said that douching with warm water is enough to remove anything unwanted for intercourse. He also noted that the rectum is not a storage place for feces - just a passageway.
Another precaution particular to anal sex is avoiding vaginal or oral contact with fecal matter, which can cause infection. All rectums have different curves, and while they are flexible, having a penis run into a wall is not pleasurable, so be aware of personal anatomy. And, as with all sexual activity, using a condom unless you are in a mutually monogamous relationship is imperative.
However, if proper precautions are taken, anal sex can be a pleasurable option to experiment with in your sex life.