Anal Sex
Anal sex most often refers to the sex act involving insertion of the penis into the rectum.[1] The term anal sex can also sometimes include other sexual acts involving the anus, including but not limited to anilingus and fingering.
It is a form of sexual behavior considered to be comparatively high in risk, due to the vulnerability of the tissues and the septic nature of the anus.[2] As the rectal mucosa provides little natural lubrication, a personal lubricant is most often required or preferred when penetrating the anus.