The use of sex toys and other activities involving the anus and rectum may be considered anal sex as well. Anal sex can be pleasurable for both the insertive partner and the receptive partner, as the anus contains many of the same kinds of nerves as the penis or clitoris.

For women, pleasure is derived from anal intercourse because the rectum shares a wall with the vagina and therefore shares some of the nerve endings associated with sexual pleasure. The anus itself also contains a number of nerves which can react pleasurably when excited.

For males, the tightness of the anus is often said to be a source of pleasure for the "active" partner in penetrative anal sex, while the presence of the prostate gland near the rectal wall is a source of pleasure during receptive anal intercourse. A sexual climax for the recipient (referred to colloquially as an anal orgasm) can occur through anal sex.

Some people view anal sex with disgust because of the relationship between the anus and feces. Sigmund Freud labelled this aversion as irrational, if not neurotic:

Where the anus is concerned it becomes still clearer that it is disgust which stamps that sexual aim as a perversion. I hope, however, I shall not be accused of partisanship when I assert that people who try to account for this disgust by saying that the organ in question serves the function of excretion and comes in contact with excrement--a thing which is disgusting in itself--are not much more to the point than hysterical girls who account for their disgust at the male genital by saying that it serves to void urine. 

Moreover, it is not uncommon for the rectum to be relatively vacant most of the time, the faeces entering only just before defecation. Some fecal matter might still remain in the rectum between movements (albeit in minimal quantity); thus some couples use enemas - either wet or dry, followed by shower or bidet use - for cleansing before engaging in any anal activity.
 
 

The term "sodomy" is imprecise, but is often used as a synonym for anal sex, particularly in older works. However, it often also refers to various other sexual activities. For instance, depending upon the jurisdiction, the legal definition of sodomy may include any non-coitus act, including oral sex and zoophilia.

Anal sex has been taboo in many Western countries since the Middle Ages, when heretical movements were sometimes slandered by rumours that their members practiced anal sex among themselves. At that time the mainstream Christian clergy was not celibate, but the highest orders of some heretical sects were, leading to rumours that their celibacy was a sign of their attraction to members of the same sex. The term buggery originated in medieval Europe as an insult used to describe the rumoured same-sex sexual practices of the heretics from the Buggre sect. This sect originated in medieval Bulgaria, where its followers were called bogomils, but when they spread out of the country they were called buggres (from the ethnonym Bulgars).

Some medieval European woodcuts portray persons kissing the anus of a goat-like figure representing the Christian Devil.

As recently as 2003, several jurisdictions in the United States had laws making anal sex and other forms of sodomy a crime. Many of these statutes purported to prohibit anal sex by same-sex partners. In 2003, John Lawrence and Tyron Garner brought a landmark suit that challenged as unconstitutional Texas's anti-sodomy law before the United States Supreme Court. Lawrence and Garner had previously been apprehended in Lawrence's home in the act of anal sex, after a neighbour had made a false noise complaint to the local police. The Supreme Court struck down the Texas law by a 6–3 vote. Five of the justices joined the deciding opinion, which overturned the Court's previous ruling on sodomy in Bowers v. Hardwick. The Court reached the conclusion that the Due Process Clause of the Fourteenth Amendment to the United States Constitution prohibited the state from regulating private behaviours between adults without furthering a legitimate state interest. The governmental interest behind the law, moral objection to homosexuality, was held to not be a legitimate interest. (See Lawrence v. Texas.)

Although it is also practiced by heterosexuals and bisexuals, anal sex is often associated with homosexual men. However, like persons of other sexual orientations, some gay and bi men enjoy sexual activities of this kind while others do not.

The vagina normally produces its own lubrication during sex; the rectum does not, so a store-bought personal lubricant is recommended by most sexologists for an enjoyable anal sex experience. According to the Centers for Disease Control and Prevention and the World Health Organization, unprotected anal sex carries more risk of STI transmission than vaginal or oral sex. To reduce the risk of transmitting STIs such as HIV, people are recommended to use a latex condom for all sexual contact which could result in transfer of bodily fluids, including anal sex.