Anal sex or anal intercourse is human sexual behavior involving the anus and rectum, especially the insertion of the erect penis into the anus. Some people enjoy activities involving these sensitive areas of the body, while others do not.
The terms sodomy and buggery are imprecise: while they are sometimes used as synonyms for anal sex, they often refer to all sexual activities that are considered unnatural, including bestiality.
Anal sex has been the subject of a strong taboo in many Western countries since the Middle Ages, when heretical movements were sometimes slandered through rumors that their members practiced anal sex among themselves. At that time, anal sex also bore associations with witchcraft. Some medieval woodcuts portray persons kissing the anus of a goat-like figure representing the Devil. To a lesser extent, anal sex remains somewhat taboo in many Western cultures and is still illegal in some jurisdictions.
Although practiced by heterosexual couples, it has often been associated with homosexual men. Like persons of other sexual orientations, some gay men enjoy sexual activities of this kind while many others do not. Heterosexual couples have sometimes used anal intercourse as a means of birth control. It should probably be considered a fairly reliable but not foolproof method, as it is still possible for semen to contact the vagina and result in pregnancy.
In several cultures (such as the Mediterranean area and Latin America) and countries (such as Brazil, where almost 50% of the population practices anal sex ), anal intercourse is widely accepted amongst heterosexuals. The reasons why it is practised other than personal preference, is not mainly as a contraception method, but mainly as a way to perform sexual activities while preserving female virginity (in the sense of having an intact hymen) until marriage, this quality being sometimes the main virtue of a wife (and its loss before a formal marriage resulting in the worst moral crime a woman could commit).
Especially in less developed areas, a severe tradition regarding the first wedding night required that "the morning after" the husband exposed on a balcony the sheet used for nuptial bed, which had to present an evident blood spot, as a proof of previous chastity of the wife, presuming that the defloration necessarily produces bleeding (since this does not necessarily happen in every case, the lack of the sheet's exposition, or of the spot, could cause serious troubles to both, even in the case of a perfectly innocent woman who simply failed to bleed). Virginity, and its "correct" loss, had to be demonstrated this way to the public, as a matter of public relevance.
The reason why women accepted the practice of anal sex before marriage has to be therefore found in the need of offering a material proof of love, so that the promised spouse would not lose interest in them, marriage being the principal scope of a woman (in these cultures), without which she would be worth nothing. It has to be recalled that in small villages there were old women (former midwives) specialised in examining the conditions of hymen before the wedding.
In the same mentality, women were not officially allowed to find pleasure in sex, therefore sex was only served as a sort of marital prostitution; in this sense, under the sole husband's determination, anal sex was a form of contraception too in the case of couples who already had too many babies, since the ignorance about other methods was total. Similar facts were reported up to a very few decades ago, and it is currently impossible to certify whether this mentality has been totally abandoned or has otherwise been substantially modified.
Gay men have long been associated with anal sex. Several cultures, such as Ancient Greece, earned a reputation as normal practitioners of homosexual anal sex ("Greek love" was a term used to refer to it.). It was custom for an older Greek man to take a young boy under his wing. He would affectionately tutor the boy, and engage in sex with him until a few years after puberty, at which point the young man chose his own pedant. Some argue that this was actually interfemoral intercourse not anal intercouse.
However, not all gay men participate in anal sex or find it enjoyable, especially after the advent of AIDS. Other gay men reserve anal sex for committed relationships.
It is not true that all gay relationships involving anal sex contain a "receiver" (taking the place of the woman) who consistently submits to anal sex, and a "giver" (taking the place of the man) who always performs it. Some relationships are structured this way (the preferred terms are top and bottom - most bottoms in this culture would be very offended by the implication that their manhood was in doubt); however, many gay men who have anal sex both top and bottom at different times. (see switch.)
In some cultures, a man who tops other men is not considered homosexual, whereas a man who bottoms is. Anglo-American queer culture does not make this distinction; both tops and bottoms who sleep exclusively with men are considered gay.
Anal sex can be very pleasurable both for the top (insertive partner) and the bottom (receptive partner). The anus contains many of the same kinds of nerves as the penis or clitoris, and stimulating the anus produces sexual pleasure.
Furthermore, the presence of the prostate gland near the rectal wall is an additional source of pleasure for a man who receives anal sex. Although male receptive anal sex has often been thought of as the exclusive province of gay men, in recent years many straight men have discovered receptive anal sex as a source of intense sexual pleasure. A woman may penetrate her male partner using her fingers or an object such as a dildo or butt plug; harnesses can be used so that a woman can wear a dildo (this is sometimes referred to as a "strap-on"). This practice often forms part of BDSM as practiced by dominatrices.
Anal sex is an effective means of transmitting most sexually transmitted diseases. In particular, it is the sexual activity which most effectively transmits the HIV (AIDS) virus. Health care professionals suggest that condoms should always be used for anal intercourse, but they should by no means be considered an absolute safeguard. The best suggestion is to avoid anal sex with anyone known to have a sexually transmissible disease, and indeed with anyone whose disease-negative status has not been determined.
Anal sex does carry some risks to health and comfort even in the absence of a risk of sexually transmitted disease. The vagina is well adapted to sex, being strengthened for this activity and secreting its own lubrication, whereas the anus and rectum are not. Thus, artificial lubrication is generally used in anal sex (oil-based lubricants like Vaseline destroy latex condoms, and the two should not be used together). The anorectal muscles are largely under involuntary control, making slow, gentle, and responsive insertion necessary to avoid pain. Additionally, nothing which has been placed in the anus should ever contact the vulva, vagina, or mouth without being thoroughly washed with soap or a similar disinfectant, to avoid infection caused by the transmission of inappropriate bacteria to this area.
It is also very important to be careful when inserting objects into the anus. Objects with edges or points can cause severe injury. Moreover, objects could get lodged in the rectum, resulting in a trip to the emergency room. (Most dildos nowadays are made with flared bases.) Additionally, nothing longer than eight inches (20 cm) -- be it a penis, a vibrator, or anything else -- should be inserted into the rectum. Objects exceeding eight inches risk colliding with the sigmoid colon. The sigmoid colon's lining isn't much stronger than a wet paper towel, and trauma can result in internal bleeding, with potentially fatal hemorrhage. It would be wise to wash carefully after every use. It is dangerous to share sex toys; if a dildo is used on more than one person, it should be covered with a condom which is changed after each use. (See masturbation for more information on the use of sex toys.)
In all forms of anal sex, it is very important for the person being penetrated to know their limits and insist that the penetrator slow down, stop, and/or withdraw if they are in pain. Like any form of sex, anal sex is rendered much more dangerous under the influence of alcohol or drugs, which reduce responses, judgment, and ability to pay attention to one's own needs.