4 reasons explained: Why sex causes UTI


Sex causes UTI, STDs, babies and orgasms. What a mess! Let’s start with UTI.

E. coli bacteria causes more than 80% of all urinary tract infections. Surprisingly, E. coli actually permanently resides in your lower intestines. And to put it simple: your poop is full of E.coli and there are always some around your ass hole.

Most E. coli are harmless and actually are an important part of a healthy human intestinal tract, they help to produce vitamin K, for example. However, when misplaced, E. coli can cause serious damage to your health. How does it happen?

How sex causes UTI

It is pretty easy to get a urinary tract infection (UTI) during sex. Anything that brings bacteria in contact with the genitals and/or urethra (this is where you pee from) can cause a UTI. Sex causes UTIs because during sex there is a higher chance for bacteria to enter your urethra.

Three engineers are discussing what kind of an engineer God is. A mechanical engineer says: “God must be a mechanical engineer, look at all the complex mechanisms of the body!”. An electric engineer argues: “No, he must be an electrical engineer! Humans operate due to electric impulses from the brain!”. A civil engineer concludes: “For what I know, God is definitely not a civil engineer: why did he put a waste line near the recreational area?”

#1 Bacteria move from your ass hole to your vagina

Here is a usual scenario: a female partner goes for #2. She wipes herself clean, but some E.coli could stay around her anus (aka “the hole she poops from”). Remember, bacteria are small, you can’t possibly see them! If this person is later having sex, these bacteria can be moved around (by the sheer force of the action 🙂 ) and make their way to her vagina.

#2 Imbalanced vaginal flora allows bacteria to grow

If woman’s vaginal flora is not healthy enough to expel the invaders, the E. coli will grow and multiply in the vagina. If later she will be sexually active again, some of the vaginal discharge could be moved “up the line” towards her clitoris and the urethra opening (aka “the hole she pees from”).

#3 E. coli eventually ends up closer to the urethra

If E. coli finds it’s way to the urethra it will eventually move up, towards the bladder, where the conditions for it’s growth are perfect! E. coli bacteria will attach itself to the bladder lining and will start to multiply at a crazy speed. Next thing she knows – it is painful to pee, she might have some blood in the urine, and overall feels crappy!

Anal play (including unprotected anal intercourse) is one of the factors that guarantee to increase your exposure to E. coli. The logic here is exactly the same. If you put a finger in your ass and then in your vagina, this would immediately transmit a gazillion bacteria into the places you don’t want them to be. For guys it is pretty mandatory to use condoms if they are engaging in anal sex if they themselves do not want a UTI.

#4 Some methods of contraception increase your chances to contract a UTI

This being said, if you are using condoms and lubricants your vagina’s normal probiotic balance will eventually get affected and it potentially could become a more welcoming place for E. coli to live and thrive in. This can also happen if you are stressed, taking hormones or just finished a cycle of antibiotics! All these factors may adversely impact the ability of your vagina to ward off E. coli. The more E. coli colonizes your vagina, the easier for it to get to your urethra. And, as a result any exposure to E. coli might lead to a UTI outbreak.

Sex increases chances of UTI, but also all kinds of other things do too. If you are not sure how you got your UTI, don’t worry. Because bacteria can so easily find its way into the urethra, it’s very common for women to have UTIs without knowing the exact cause of the infection.

Sometimes the urethra gets irritated from sexual activity and you might then get urinary symptoms like frequency, urgency and burning. This is called “honeymoon cystitis”, which is a misleading term. In reality, this should be called “honeymoon urethritis”. The difference is that the symptoms are present due to mechanical irritation of the urethra (your pee hole) and the bladder is not affected. In this case the symptoms are not caused by bacteria or STDs and are gone in couple days. If you repeatedly experience these symptoms and your urine sample is clean, use a lubricant and make sure your partner is gentle during sex and takes good care of his manicure!

There are other ways how E. coli can travel to your vagina

  • Wiping from back to front: The more you expose your genitals to fecal matter (poop!) the higher the chances to infect yourself.
  • Toilet water back splash. Yikes. No comments…
  • Wearing thongs: Some believe that wearing thongs would promote spreading bacteria from your anus toward your vaginal opening.

Lastly, UTIs can also be caused by sexually transmitted diseases (STDs). When a UTI is caused by an STD, the infection is most often only in the urethra — not the bladder, however the symptoms could feel the same way.

Remember this facts to protect yourself:

  • Bacteria E. coli is a part of normal bacterial flora in our intestines, rectum and human poop.
  • It is easy for E. coli to travel to your vagina opening and from there, especially during sex-play, to your urethra.
  • E. coli normally cannot survive in the healthy vagina for too long (too acidic for its taste), but it feels perfectly fine residing in the urethra and bladder. You, on the other hand, get all the nasty symptoms of UTI if E. coli is colonizing your urethra or bladder.

However, sex is not the only reason. Here is a summary of 5 factors that cause UTI.

Do this to protect your health:

  1. Buy potent probiotics to improve vaginal flora
  2. Try D-Mannose supplement
  3. Make sure your urine has low pH


  1. Do you still get utis after using these preventative measures? I have a recurring uti problem ever since I became sexually active. Never had them before. Now I got about 6 or 7 this past year! Doctor is recommending I take a small dose of antibiotic every time after I have sex. Have you heard about this method? Thoughts? I’m not sure how I feel about it…

    • Hi Ashley,
      No, I am not getting UTIs anymore (knock on wood). Yes, I’m familiar with this recommendation (you can read “About me”). If your UTIs are caused by sex, probiotics and D-Mannose combo might be helpful to supplement your prevention strategy. I believe this is what helped me. Best of luck!

  2. Why don’t you mention the role of an asymptomatic male putting his urethra into your body? Because that’s what happens when you have sex; his genital passage and urethra are one. And he’s giving you a good dose of his germs every time. Treat him, you might find yourself better off too!

    • Hi Michelle,
      Thank you for your comment. Funny, but men in most cases do not have bacteria causing UTI in their urethra (the only exception would be unprotected anal sex). Men do have other bacteria of course, but research in microbiota shows that their genital flora is much more influenced by ours rather than other way around. So unless he has an acute UTI, he would not contribute to our problem other than mechanically moving our own bacteria around 🙂

  3. Hello,
    Thank you for your post. I’m concerned I may get a UTI and I was wondering if you can get one by rubbing a penis between the butt cheeks (while on top of the male and not deep enough to touch the anus) and then rubbing the penis on the clitoris.


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