Anal sex is stimulation of the anus during sexual activity. It can be done in several different ways: manually, orally or by anal intercourse.
Anal sex can be the primary form of sexual activity or it can accompany other types of stimulation. For instance, couples sometimes include manual stimulation of the anus (either lightly rubbing the rim or inserting a finger into the anus) during vaginal intercourse. Others use the tongue in a similar fashion for oral stimulation.
Anal intercourse is the insertion of a man's penis into his partner's rectum. Although anal sex is often thought of as a strictly homosexual activity, many heterosexual couples enjoy it too.
Anal penetration can be pleasurable, but it can also be a source of physical discomfort. The muscle on the outside of the rectum, called the anal sphincter, ordinarily tightens if stimulated, which means that attempts at insertion of the penis, or even a finger, may be uncomfortable even if done slowly and gently. If penetration into the anus is forced, injury is possible. It is helpful to use a lubricant liberally and to relax and gradually dilate the sphincter by gentle manual stimulation before attempting penetration.
Some people empty the rectum with a disposable enema before anal intercourse. Since the rectum contains bacteria that are capable of causing infection, anything -- fingers, objects, a penis -- that has contact with the anus should not subsequently be in contact with the vagina or mouth until it has been thoroughly washed.
Some people have strong negative attitudes toward anal sex, whether it takes place between homosexual or heterosexual couples. They may think of it as being unclean, unnatural, perverted, disgusting or simply unappealing. It is sometimes regarded as the ultimate in depravity and has regularly been condemned by religious and secular authorities.
Historically, religious groups have objected because a woman cannot get pregnant through anal sex, and these groups approved of sexual intercourse only for the purpose of reproduction.
Anal sex was up until recently subject to legal restrictions in many states, even between married couples. In general these statutes refer to anal sex acts as "crimes against nature," going back to the view that heterosexual intercourse, with its reproductive potential, is the only natural, healthy, nonsinful way of having sexual relations. These laws are strongly biased toward the prosecution of homosexuals because penetrative anal sex is far more common among gay men than it is among heterosexual couples.
It’s important to remember that HIV can be transmitted through anal sex, especially anal intercourse. The risk of HIV transmission is greater than in vaginal intercourse because the lining of the rectum tears more easily than the vagina. The resulting skin breaks and bleeding increase the possibility of the transmission of bodily fluids containing the virus that causes AIDS.
Those who engage in either vaginal or anal penetrative sexual acts should use latex condoms, the best way to reduce the likelihood of HIV transmission
Condoms are excellent for preventing the transmission of sexually transmitted diseases, including HIV/AIDS. Condoms must be made of latex, not lambskin or other substances, to prevent STDs.
Anal Warts can be sexually transmitted from anal sex; check out that article for more. They aren't always an STD, however.