This research is being done to compare the results of tests for diagnosing sexually transmitted infections (STI) from rectal samples. Specifically, this study will test for gonorrhea and Chlamydia from rectal samples and compare the results between standard culture and newer technology (nucleic acid amplification testing otherwise know as "NAAT") used to detect these infections. Gonorrhea and Chlamydia are STIs (infections you get from having sex with someone who is infected). Infections in the rectum may cause symptoms such as rectal discharge, itching and/or pain or may be asymptomatic (no symptoms present). Since these infections are sexually transmitted, it is important to have accurate tests to diagnose and treat these infections to prevent them from being passed onto a sexual partner.