Anal sex -- Mmm tasty! (pt. 2)

Homosexual
19th-century erotic interpretation of Hadrian and Antinous, by Paul Avril

In recent decades, particularly in Western cultures, anal sex has been popularly associated with male homosexuality and men who have sex with men (MSM). Among MSM who have anal sex, the insertive partner is referred to as the top or active partner. The man being penetrated is referred to as the bottom or passive partner. Preference for either is referred to as versatile. Not all MSM engage in anal sex, and some groups such as frot[18] advocacy groups actively denounce anal sex as degrading toward the receptive partner and an unnecessary health risk. This viewpoint cites the increased HIV risk and physiological differences of the anus from the vagina.
Prostate stimulation
Diagram showing location of prostate

In the receiving partner, being penetrated can produce a pleasurable sensation due to the inserted penis rubbing or brushing against the prostate through the anal wall. Penetration can be painful if the bottom partner's anus is not properly lubricated.

The prostate gland (also known as the "male G-spot" or "A-spot") can be stimulated during anal intercourse.[19]

Stimulation of the prostate gland can result in pleasurable sensations and can lead to a distinct type of orgasm in some cases. The prostate is located next to the rectum and is the larger, more developed[20] male homologue to the Skene's glands, which are believed to be connected to the female "G-spot".[21] The Skene's glands are sometimes referred to as the "female prostate",[22] and which are located around the urethra and can be felt through the wall of the vagina.

Prevalence

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".[23]

In the 1950s in the United Kingdom, it was thought that about fifteen percent of male homosexuals practiced the method.[24] The Gay Urban Men's Study (P.I. Stall, UCSF) and the Young Men's Study (YMS, PI Osmond/Catania, UCSF), indicate that 50% of men surveyed engage in anal sex. The Laumann study claims that 80% of gay men practice it, while the remaining 20% never engage in it at all.

A survey conducted from 1994 to 1997 in San Francisco by the Stop AIDS Project indicated that over the course of the study, among men who have sex with men, the proportion engaging in anal sex increased from 57.6% to 61.2%.[25]

Health risks
Mucous membranes of the rectum

Anal sex exposes participants to two principal dangers: infections, due to the high number of infectious microorganisms not found elsewhere on the body, and physical damage to the anus and the rectum due to their vulnerability.

Recent reports have documented that risky behavior is on the rise among men who have sex with men.[25] Likewise, among men who have sex with women, a 1992 study of socially and sexually active Puerto Rican men indicated that of the more than 40% who reported having anal sex with women, very few had used condoms.[26] Among gay men, anal sex without the use of a condom is referred to as barebacking.

HIV/AIDS and other infectious diseases

Among the diseases with which anal sex is associated are HIV,[27] human papilloma virus (HPV) (which can increase risk for anal cancer)[28] typhoid fever[29] and various diseases associated with the infectious nature of fecal matter or sexual intercourse in general. Among these are: amoebiasis; chlamydia; cryptosporidiosis; E. coli infections; giardiasis; gonorrhea; hepatitis A; hepatitis B; hepatitis C; herpes simplex; human papillomavirus; Kaposi's sarcoma-associated herpesvirus (HHV-8)[30]; lymphogranuloma venereum; pubic lice; salmonellosis; shigella; syphilis; tuberculosis.[31][32][33]

The high concentration of white blood cells around the rectum, together with the risk of cuts to the rectum and that one of the functions of the rectum is to absorb fluid, increases the risk of HIV transmission because the HIV retrovirus reproduces within the immune system's T-cells/CD4 cells. Use of condoms and other precautions are a medically recommended way to lessen risk of infections. Unprotected receptive anal sex is the most risky sexual behavior in terms of HIV transmission.[34][35][36]

Increased risk of anal cancer due to HPV

Most cases of anal cancer are related to infection with the human papilloma virus. The incidence of the disease has jumped 160% in men and 78% in women in the last thirty years, according to a 2004 American study. The increase is attributed to changing trends in sexual behavior and tobacco use. Current use of tobacco increased the incidence of anal cancer four-fold, while a history of multiple sex partners (fifteen or more) or receptive anal sex increased the incidence seven-fold.[37]

Physical damage

Physical damage to the rectum and anus can manifest as generalized ano-rectal trauma, hemorrhoids, anal fissures,[31] and rectal prolapse. An insufficient amount of lubricant can make it especially painful or injurious.[38] Damage is more likely if intercourse is forcible or aggressive, if alcohol or other drugs have dulled sensitivity, if communication is poor, or if technique is clumsy.

Anal incontinence

A 1997 study published in the American Journal of Gastroenterology found no difference in levels of incontinence between homosexual men who engaged in anal sex and heterosexual men who did not, and severely criticised an earlier 1993 study published in the Journal of the Royal Society of Medicine which had found that fourteen out of a sample of forty men receiving anal intercourse experienced episodes of frequent anal incontinence for its inclusion of flatulence in its definition of incontinence.

Dr. Jack Morin recommended kegel exercises to prevent loss of muscle tone from anal fisting or insertion of large objects in a presentation of clinical aspects of anal sexuality, delivered at the 1998 joint conference of the Society for the Scientific Study of Sexuality and the American Association of Sex Educators. He added, however, that he had never personally observed "loosening" in any of his patients.

Cultural issues
A shunga print depicting a man and a youth

Historically, a number of cultures have recorded the practice of anal intercourse between men. The males who participated in such relationships often did not do so exclusively, as participation in these relationships between men did not preclude sex with women. Such relations have also been documented as taking place in houses of prostitution, which provided youths or young men.

Ancient and non-Western cultures

The term "Greek love" has long been used to refer to the practice, and in modern times, "doing it the Greek way" is sometimes used as slang for anal sex. However, homosexual anal sex was far from a universally accepted practice in Ancient Greece. It was the target of jokes in surviving comedies; Aristophanes mockingly alludes to the practice, claiming that "Most citizens are europroktoi (wide-arsed) now."[42] While pedagogic pederasty was an essential element in the education of male youths, these relationships, at least in Athens and Sparta, were expected to steer clear of penetrative sex of any kind. There are very few works of pottery or other art that display anal sex between older men and boys, let alone with adult men. Most such works depict fondling or intercrural sex, which was not condemned for violating and feminizing the boys. Other sources make it clear that the practice was criticized as shameful,[43] and seen as a form of hubris.[44]
Two Roman males in a lupanar; Warren Cup, British Museum

In later Roman age Greek poetry, anal sex became a common topos, represented as taking place with "eligible" youths: those who had attained the proper age but had not yet become adults. Seducing children into the practice was considered very shameful for the adult, and having such relations with a male who was no longer adolescent was considered more shameful for the young male than for the one mounting him. Greek courtesans, or hetaerae, are said to have frequently practiced heterosexual anal intercourse as a means of preventing pregnancy.[45] The acceptability of anal sex thus varied with the time-period and the location, as Ancient Greece spanned a long time and stretched over three continents and two major seas.

For a male citizen to take the passive (or receptive) role in anal intercourse was condemned in Rome as an act of impudicitia (immodesty or unchastity). Free men, however, frequently took the active role with a young slave, known as a catamite or puer delicatus. In fact the Romans thought of anal sex as something specifically "Greek," although Roman men often availed themselves of their own slaves or others in this way.[46]

In Japan, records (including detailed shunga) show that at least some men in relationships with other men did engage in penetrative anal intercourse.
Man and woman having anal sex. Ceramic, Moche Culture. 300 A.D. Larco Museum Collection

Christianity

In Christian countries it has often been referred to euphemistically as the peccatum contra naturam (the sin against nature, after Thomas Aquinas) or Sodomitica luxuria (sodomitical lusts, in one of Charlemagne's ordinances), or peccatum illud horribile, inter christianos non nominandum (that horrible sin that among Christians is not to be named). Although most Christian religions disapprove of anal sex, others believe it to be acceptable.