If you’re reading this, you may either have decided to have anal sex for the first time or added it to your regular sexual repertoire. Either way, congratulations! Thanks to the clusters of nerve endings around that region (and maybe the sense of inhibition that comes with partaking in the act, depending on how you see it), anal sex can feel incredibly good for some people. But there’s one major anal mistake that can put your health at risk, and ob/gyns want you to avoid it so you don’t have to make an emergency appointment with them because of your very angry vagina.
Basically, you shouldn’t ever switch from anal to vaginal sex without using a new condom. “This is one of the regular points I always make when [patients ask] about anal intercourse,” Mary Jane Minkin, M.D., a clinical professor of obstetrics and gynecology at Yale Medical School, tells SELF. “I don’t give a damn what you do, but that’s the one thing I discourage. I’m not going to say the vagina is sterile and there are no bacteria there—there are tons, but there are even more in the anal area,” says Minkin.
Once it hits your vagina, that new-in-town bacteria might wreak havoc. “The bacteria in the GI tract, rectum, and anus should be there because they serve a purpose, but when they’re moved to the reproductive tract, they can cause quite a few issues,” Jamil Abdur-Rahman, M.D., board-certified ob/gyn and chairman of obstetrics and gynecology at Vista East Medical Center in Waukegan, Illinois, tells SELF.
One potential problem is bacterial vaginosis, which Abdur-Rahman says in this case “could be a little tougher to treat [than regular bacteria vaginosis] because it’s caused by species of bacteria you don’t usually see in the vagina.”
It can also contribute to pelvic inflammatory disease, a condition that happens when harmful bacteria or viruses migrate from the vagina to the uterus, fallopian tubes, or ovaries—and if left untreated, it can lead to fertility issues.
As if that weren’t enough, switching from anal to vaginal sex without also switching condoms is an easy way to get your garden variety urinary tract infection. “The urethra is so close to the vagina, and on average the female urethra is around 3 or 4 centimeters, so the bacteria doesn’t have far to travel to get up to the urethra and into the bladder,” says Abdur-Rahman. Without proper treatment, UTIs can eventually lead to kidney infections, so they’re no walk in the park.
The good news is that this is an easy problem to avoid by using a new condom any time you’re transitioning from anal to vaginal play (that stands whether your partner is using their penis, a sex toy, or their fingers). If your action is unfolding in the reverse of that timeline, no need to grab a new rubber or worry about your health—your vaginal bacteria is no match for your butt, the experts say.
So, what about if you two have been tested and are used to having condom-free fun? You might still want to use a condom or latex gloves depending on what you’re doing, at least for the anal portion of the evening. Washing the penis/sex toy/hands in question with water and soap is better than nothing, but still not ideal because you’d have to wash them “pretty aggressively” to clean off all the bacteria, says Abdur-Rahman. “I don’t think most people are going to do that,” he (rightfully) adds.
Better to play it safe in the first place and bag it before the butt play.