of bacteria and viruses, including HIV. This includes penetration of the anus by fingers, hands, or sex toys such as dildos. Also, condoms may be more likely to break during anal sex than during vaginal sex, increasing the risk of STI transmission. The main risk which individuals are exposed to when performing anal sex is the transmission of HIV. Other possible infections include hepatitis A, B and C; intestinal parasite infections like Giardia; and bacterial infections such as Escherichia coli. Anal sex should be avoided by couples in which one of the partners has been diagnosed with an STI until the treatment has proven to be effective. In order to make anal sex safer, the couple must ensure that the anal area is clean and the bowel empty and the partner on whom anal penetration occurs should be able to relax. Regardless of whether anal penetration occurs by using a finger or the penis, the condom is the best barrier method to prevent transmission of STI. Enemas should not be used as they can increase the risk of HIV infection and lymphogranuloma venereum proctitis. Since the rectum can be easily damaged, the use of lubricants is highly recommended even when penetration occurs by using the finger. Especially for beginners, using a condom on the finger is both a protection measure against STI and a lubricant source. Most condoms are lubricated and they allow less painful and easier penetration. Oil-based lubricants damage latex and should not be used with condoms; water-based and silicone-based lubricants are available instead. Non-latex condoms are available for people who are allergic to latex made out of polyurethane or polyisoprene. Polyurethane condoms can safely be used with oil-based lubricant. The "female condom" may also be used effectively by the anal receiving partner. Anal stimulation with a sex toy requires similar safety measures to anal penetration with a penis, in this case using a condom on the sex toy in a similar way. It is important that the man washes and cleans his penis after anal intercourse if he intends to penetrate the vagina. Bacteria from the rectum are easily transferred to the vagina, which may cause vaginal and urinary tract infections. When anal-oral contact occurs, protection is required since this is a risky sexual behavior in which illnesses as hepatitis A or STIs can be easily transmitted, as well as enteric infections. The dental dam or plastic