I got pointed to a thread on Fetlife about switching from anal sex to oral sex (ass to mouth, or ATM in porn parlance) so I went on over to take a look. (For those who aren’t familiar with it, Fetlife is a social networking site for the BDSM crowd. You’ll need to log in to see the discussion.)
As usual, the debate centers on whether doing ATM without cleaning up is unsafe. Some people are arguing that unless you already have hepatitis or some other infection, you can’t get it from ATM and therefore it’s reasonably safe. Since there’s a fair amount of confusion on this, I decided to ask an expert.
I contacted a public health nurse who tracks certain diseases, gets people the medical care they need, and takes samples of all sorts of bodily secretions to the lab to check for infections. That makes her an authority when it comes to illness and feces- she has to keep track of things like salmomella, giardia, and typhoid, all of which are spread by feces contamination.
It turns out that you can, in fact, make yourself sick by introducing E. coli into your upper digestive tract. E. coli is a bacteria that lives in the lower intestine and it helps us digest our food. But when it gets into the upper part of our digestive system, it can cause bloating, flatulence, and diarrhea (aka one type of food poisoning). So yes, you can make yourself sick by getting your own E. coli in the wrong part of your digestive system. Having said that, there are many different strains of E. coli and different people have varying levels of tolerance for it, so it’s certainly possible for some people to do ATM and never have a problem, while others have a strong negative reaction.
Given that ATM has become more common in porn, I asked about enemas and safety. While an enema may clean out any feces still in the colon, it can also move bacteria from further up in the gut to further down, so it’s not a guarantee of safety with respect to E. coli. It’s also possible to have a subclinical typhoid, salmonella or giardia infection (that’s an infection that doesn’t have symptoms), and performing ATM can then increase your bacterial load enough to become clinical. To make things worse, having just reinfected yourself, you can extend the length of illness and communicability.
If you’re performing oral-anal sex on someone else, you’re potentially coming into contact with their E. coli and any other intestinal bug they may have. It’s also possible to spread an STI or a digestive system infection through oral-anal play, but only if one of the partners already has it. But remember that not all infections result in symptoms, so you may not always know your risk.
If you do want to do this kind of play, you can use a condom for the anal sex and take it off when you switch to oral sex or you can use a dental dam to make oral-anal play safer. Or you can take your chances, but I figure it’s best when you know what your odds are.