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Anal sex

What is anal sex?

Anal sex refers to sexual intercourse that involves penetration of the anus with a penis, fingers or other implements. It can also describe stimulating the anus in oral sex. A recent survey estimates around 31% of people in the UK engage in anal sex - both gay and heterosexual. While any kind of sexual activity carries a risk of sexually transmitted infections (STIs), penetrative anal sex poses a higher risk because the anus is more susceptible to infection.

Risks of anal sex

Some people engage in anal sex because they find it more stimulating than other sexual activity. The anus is narrow and contains lots of nerve endings, which make it an easily stimulated and highly sensitive erogenous zone. However, the practice does involve more risk than vaginal sex for a number of reasons, including:

  • The anal lining is thin and easily torn and damaged
  • The anus lacks the natural lubrication of the vagina
  • Tissue inside the anus does not have a protective barrier of dead skin cells
  • The anus contains lots of bacteria (from faeces) that can pass into the blood stream if tissue is damaged.


A number of STIs can be passed on during anal sex. They include:

Studies suggest the receptive partner in penetrative anal sex is 30 times more likely to be at risk from exposure to HIV than a receptive partner in vaginal sex. Anal sex without a condom - sometimes called 'barebacking' is an even greater HIV risk.

Other risks

  • Oral-anal sex - sometimes referred to as ”rimming” can spread infections like HPV, hepatitis B or E. coli.
  • Exposure to the human papillomavirus (HPV) may lead to the development of anal warts and anal cancer.
  • Practising vaginal sex after anal sex can lead to vaginal and urinary tract infections.
  • Repeated anal sex risks weakening the anal sphincter muscle and causing incontinence.

Pregnancy and anal sex

There is a risk of pregnancy for heterosexual couples engaged in anal sex. This is because semen can be released unintentionally near the opening to the vagina. For this reason, it is advisable to take the normal contraceptive precautions you would take during vaginal sex.

Serious injury and anal sex

Serious injury during anal sex is a rare occurrence, but it does happen. If anal sex causes bleeding this may be caused by a haemorrhoid, a tear or a more serious and dangerous perforation of the bowel. If you suspect this has happened, seek immediate medical help.

Reducing the risk of anal sex

There is no way to completely eradicate the risks involved in anal sex but there are some measures that may somewhat reduce those risks. They include:

  • Using water based lubricant during anal sex, but this does not rule out tearing
  • Using condoms to protect against STIs
  • Using a new condom if you engage in vaginal sex after anal sex
  • Avoid inserting a penis into the mouth or vagina after anal sex
  • Relaxing and lying on the stomach may make anal sex less difficult
  • Always stop if sex is painful
  • Seek medical advice immediately if you experience bleeding, discharge, sores or lumps

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