Background: Currently, individuals at risk for sexually transmitted diseases (STDs) are tested extragenitally only if indicated, most often when there is a history of self-reported symptoms or self-reported anal sex. The sensitivity of such selective symptom-and sexual history-based testing for detection of anorectal STD has not been determined. Methods: All men having sex with men (MSM) and swingers (heterosexual couples who have sex with other heterosexual couples and their self-identified heterosexual sex partners) attending our STD clinic (consults: n = 1690) from January 2010 until February 2011 were universally tested for urogenital, anorectal, and oropharyngeal Chlamydia trachomatis and Neisseria gonorrhoeae infections (STD). We comp...