Besides the shared anatomy of the aforementioned sensory nerves, orgasm by indirect stimulation of the clitoris or G-spot area through anal penetration may be aided by the close proximity between the vaginal cavity and the rectal cavity.
Stimulation from anal sex can additionally be affected by popular perception or portrayals of the activity, such as erotica or pornography.
Indirect stimulation of the clitoris through anal penetration may also be caused by the shared sensory nerves, especially the pudendal nerve, which gives off the inferior anal nerves and divides into two terminal branches: the perineal nerve and the dorsal nerve of the clitoris.
but it is typically described as being located behind the female pubic bone surrounding the urethra and accessible through the anterior wall of the vagina; it and other areas of the vagina are considered to have tissue and nerves that are related to the clitoris.
Mc Bride's 2010 clinical review on heterosexual anal intercourse and other forms of anal sexual activity, it is suggested that changing norms may affect the frequency of heterosexual anal sex.
Mc Bride and her colleagues investigated the prevalence of non-intercourse anal sex behaviors among a sample of men (n=1,299) and women (n=1,919) compared to anal intercourse experience and found that 51% of men and 43% of women had participated in at least one act of oral–anal sex, manual–anal sex, or anal sex toy use.
By contrast, people also regard anal sex as a natural and valid form of sexual activity that may be as fulfilling as other desired sexual expressions.
They may regard it as an enhancing element of their sex lives or as their primary form of sexual activity.
The Human Sexuality: An Encyclopedia states that "the inner third of the anal canal is less sensitive to touch than the outer two-thirds, but is more sensitive to pressure" and that "the rectum is a curved tube about eight or nine inches long and has the capacity, like the anus, to expand".
In pornography, anal sex is commonly portrayed as a desirable, painless routine that does not require personal lubricant; this can result in couples performing anal sex without care, and men and women believing that it is unusual for women, as receptive partners, to find discomfort or pain instead of pleasure from the activity.
By contrast, each person's sphincter muscles react to penetration differently, the anal sphincters have tissues that are more prone to tearing, and the anus and rectum do not provide lubrication for sexual penetration like the vagina does.
Prostate stimulation can produce a "deeper" orgasm, sometimes described by men as more widespread and intense, longer-lasting, and allowing for greater feelings of ecstasy than orgasm elicited by penile stimulation only.
The vaginal walls contain significantly fewer nerve endings than the clitoris and anus, and therefore intense sexual pleasure, including orgasm, from vaginal sexual stimulation is less likely to occur than from direct clitoral stimulation in the majority of women.