Unless you and your partner are in a committed monogamous relationship and have both been tested recently, you should use condoms during anal sex to reduce to risk of sexually transmitted infections and HIV, Dr. Chinn says. Yup, you can get STIs in your butt.
Using a new condom is especially important if you’re switching from anal to vaginal penetration so you can avoid moving bacteria from your anus to your vagina or urethra. Your anus is home to all kinds of bacteria your vagina and related parts aren’t used to—namely, gastrointestinal (GI) bacteria, like E. coli. When this bacteria reaches your vagina, it can cause vaginal infections, like bacterial vaginosis, which can lead to vaginal itching, burning during urination, a “fishy” vaginal odor, and gray, white, or green vaginal discharge, according to the Mayo Clinic. It can also spread to your urethra, where it can cause a urinary tract infection. According to the Mayo Clinic, this can cause symptoms like constantly needing to pee, then a burning sensation when you do, along with cloudy urine and pelvic pain.
Long story short? If you insert anything into your anus, clean it off and/or roll on a new condom before putting it into your vagina.
Worth noting: Even if you and your partner aren’t worried about STIs or HIV, using a condom may make you feel more comfortable if…mess…is a concern.