Anal sex

Anal sex is a form of human sexual behavior which encompasses many sexual acts involving the anus, anal cavity, sphincter valve and/or rectum. The term anal sex, however, is often restricted to anal intercourse: the insertion of the erect penis into the rectum.

It is a form of sexual behavior considered to be comparatively high in risk, due to the vulnerability of the tissues and the septic nature of the anus.As the rectal mucosa provides little natural lubrication, a lubricant (such as a personal lubricant, for example) is most often required or preferred when penetrating the anus.

Male-male

In modern times, particularly in Western cultures, anal sex has been popularly associated with gay and bisexual men. Anal sex has also been associated with the spread of HIV, starting in the early years of the discovery of the disease. This resulted in gay bathhouses in some American cities being shut down by public-health authorities.

Among gay men who have anal sex, some consistently take the top (insertive) or bottom (receptive) role, but this is not always the case: some men who have anal sex act as both top and bottom at different times. This is known as "versatile" or "switch". Common slang terms that identify the consistently insertive and receptive roles are (in the USA) "pitcher" and "catcher," respectively and (in the UK) "active" and "passive".

In men, anal sex can produce a pleasurable sensation due to the stimulation that the partner's erect penis causes when rubbing or massaging the prostate (see below). Penetration can be painful for some men depending on their rectal anatomy or on the amount of lubrication used during penetration. While some men obtain strong sexual pleasure from being penetrated, occasionally becoming so aroused as to even avoid the need for penile stimulation to reach orgasm, others may find it discomforting at first or, at the other end of the spectrum, completely painful or unenjoyable

Male-female

In modern Western countries anal sex is reported as being a widely practiced, if still minority, form of intercourse between men and women. In some cultures, receptive anal intercourse by heterosexual partners is widely accepted. One reason is that there is very low risk of unwanted pregnancy via unprotected anal intercourse (though this is not an absolute guarantee, because semen can leak from the anus, cross the perineum, and enter the vagina). Also, anal sex is sometimes seen as preserving female virginity because it leaves the hymen intact. Another reason is that the anus is considered to yield more tactile pleasure for the penis, being tighter than the vagina.

Alternatively, the male may take the receptive role in heterosexual anal sex, usually aided by sex toys. The practice of pegging, in which a woman wearing a strap-on dildo penetrates her male partner, is gaining acceptance. Moreover, due to the proximity of the prostate gland to the rectum, it has been suggested that males may derive greater satisfaction in this manner than females.

Anal sex and female virginity

Though more often applied to first penetration, the concept of "technical virginity" is sometimes conceived as resting solely on vaginal penetration. In Norman Mailer's novel Harlot's Ghost, a character states that in Italy, an unmarried woman had to be "a maiden before and a martyr behind", implying that such women were obliged to submit to anal sex and that anal sex was painful.

In other cases, first anal intercourse is conceived of as ending a separate virginity from first vaginal intercourse, with varying degrees of seriousness. In a Rolling Stone interview, comedian Sarah Silverman joked: "I didn't lose my virginity until I was twenty-six. Nineteen vaginally, but twenty-six what my boyfriend calls 'the real way.'"

Frequency

Determining the proportion of people that engage in anal sex, and the frequency with which they do so, is rather difficult. Sexual surveys tend to reflect whether those surveyed have ever had anal sex, or whether they have had anal sex in the last year, instead of distinguishing between those who have tried it one or a few times and those who regularly have anal sex. It is also thought that a reason for the difficulty is the difficulty of collecting data on a practice that remains highly stigmatized in many countries. According to a 2004 report, "Some research suggests that one in four heterosexuals in the US has tried anal sex and for one in 12, it is an occasional or episodic practice. Other surveys suggest that seven times as many women as gay men engage in anal intercourse, a figure reflecting the greater overall heterosexual population."

While at the present time it is reported more frequently among same-sex couples, according to Dr. John Dean and Dr. David Delvin, "in absolute numbers, it is hypothesized that more heterosexual couples have anal sex than homosexual couples".