Anal–oral sex (Anilingus)
http://en.wikipedia.org/wiki/Anal%E2%80%93oral_sex
Anal–oral sex, also referred to or described as anal–oral contact or anilingus (from anus + lingus (Latin Lingere: to lick)), also spelled analingus, is a form of oral sex involving contact between the anus or perineum of one person and the mouth (lips) or tongue of another. Non-clinical, slang terms include rimming, rim-job, salad tossing, butt licking and eating ass. It is performed by people of all sexual orientations. Depending upon the context in which it is performed, this sex act can either be used for personal pleasure among consenting parties or as a form of erotic humiliation.
Technique
Anilingus involves a variety of techniques to stimulate the anus including kissing, licking, and sliding the tongue in and out of the anus. Pleasure for the receiver comes from the sensitive nerve endings surrounding the anal opening, which are not typically stimulated by the tongue and lips.Mutual anilingus can also be done in the 69 position.
Health risks and prevention
There are many health problems that can result from practicing unsafe anilingus, because of the presence of bacteria, viruses or parasites on or in the anus or rectum. These include Hepatitis A, Hepatitis B, Hepatitis C, intestinal parasites, chlamydia infection, poliomyelitis, human papillomavirus (HPV), gonorrhea, Herpes simplex virus, conjunctivitis, and other sexually transmitted diseases.[4] Applying the mouth to the genitals immediately after applying it to the anus can inadvertently introduce the bacterium Escherichia coli ("E. coli") into the urethra, leading to a urinary tract infection. HIV/AIDS is not believed to be easily transmitted through anilingus, although experts assert that there is a risk of acquiring HIV from anilingus.[5]
Frequent anilingus with casual partners increases the health risks associated with the practice. Generally, people carrying infections that may be passed on during rimming will appear healthy. Parasites may be in the feces if poorly cooked meat was consumed. Hepatitis A traces in feces apply only if the infected person has eaten contaminated food. Hepatitis C is rare although possible if the receiver has trace amounts of infected blood through his/her anus or feces.
If the receiving partner has wounds or open sores on their genitals, or if the giving partner has wounds or open sores on or in their mouth, or bleeding gums, this poses an increased risk of STD transmission. Brushing the teeth, flossing, undergoing dental work, or eating crunchy foods such as potato chips relatively soon before or after performing anilingus also increases the risk of transmission, because all of these activities can cause small scratches on the inside of the lips, cheeks and palate. These wounds, even when they are microscopic, increase the chances of contracting STDs that can be transmitted orally under these conditions. Such contact can also lead to infections from common bacteria and viruses found in and around the genitals and anus.
Another recent study suggests a correlation between oral sex and throat cancer. It is believed that this is due to the transmission of HPV because this virus has been implicated in the majority of cervical cancers. The study concludes that people who had one to five oral sex partners in their lifetime had approximately a doubled risk of throat cancer compared with those who never engaged in this activity and those with more than five oral-sex partners had a 250% increased risk.
Owing to disease risks, many medical professionals advise the use of dental dams when performing or receiving analingus with a partner whose STD status is questionable. A makeshift dental dam can be made out of a condom. Using a real dental dam is preferable, as real dental dams are larger, and the makeshift version may be accidentally damaged during the cutting procedure. Plastic wrap may also be used, but this is less preferable because it is not designed to prevent the passage of bacteria through its material. Also, the thickness of plastic wrap can reduce sensation. Some choose to perform analingus after giving the receiving party an enema, which washes out most, if not all, feces from the rectum. However, a person who receives an enema may still have harmful microbes in his/her anus after the procedure is finished, as enemas are not designed to remove bacteria. All an enema does is flush out that part of the body. It does not sterilize it