Sex causes UTIs, STDs, babies, and orgasms. What a mess! But let’s focus only on UTIs for today.
Escherichia coli (E. coli) bacteria cause between 80 and 90% of all urinary tract infections that affect up to half of all women during their lifetime. Yet, the E.coli don’t normally start out in your bladder, they live in your large intestine or colon.
To put it simply: your poop is full of E. coli and there is always bacteria living in and around your anus.
Fear not, however: most E. coli are harmless and are actually an important part of a healthy human intestinal tract. For example, did you know that they help produce vitamin K?
However, E. coli can cause serious damage to your health when it leaves its rightful place in your intestinal tract. So, how does this happen? Watch this short video for a lively demonstration:
Sex should not cause a UTI
Before we dive into mechanics of E. coli transmission, I’d like to make an important segway.
If you are healthy, sex should not be the reason that you have recurrent UTIs!
If sex causes a UTI, you should find out why. Look for an underlying condition that weakened your immune system enough in the first place to trigger a UTI.
Again: sex is not a cause for UTI. Sex is simply a risk factor for UTIs.
If you keep getting UTIs after sex, it is really important to address the underlying cause of your UTIs. For many women, sex may trigger a UTI if there is an imbalance in their vaginal flora.
How sex causes UTI
If you already have an imbalanced vaginal flora, it is pretty easy to get a UTI after sex. Any activity that moves the UTI causing bacteria from their place of residence- the anus (or the genitals, if you have abnormal vaginal flora)- to the urethra can cause a UTI. Sex can sometimes trigger a UTI because there is a higher chance for bacteria to enter your urethra and vagina during sex and sex might be slightly inflammatory due to the friction.
Consider this joke that illustrates the point:
Three engineers are discussing the type of 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: “From what I know, God is definitely not a civil engineer: why did he put a waste line near the recreational area?”
By the way, for folks who suffer UTIs after sex, I wrote a step-by-step guide on how to start solving this problem.
#1 Bacteria move from your anus to your vagina
There will always be some bacteria around your anus, no matter how hygienic you are.
During sex, bacteria can move around due to the sheering forces and can more easily make their way into the vagina.
#2 Imbalanced vaginal flora allows bacteria to grow
If your vaginal flora is not healthy enough (good vaginal bacteria like the Lactobacillus species and an acidic environment) to expel the invaders, the E. coli can grow and multiply within the vagina.
If later, you are sexually active again, some of the vaginal discharge containing the pathogenic bacteria could move up toward the urethra opening.
#3 E. coli ascends to the urethra
If E. coli find their way to the urethra, they can eventually move up toward the bladder, where the conditions for bacterial growth are perfect.
E. coli bacteria will attach themselves to the inner bladder lining (urothelium) and start to multiply rapidly. Next thing you know: it is painful to pee, there is blood in your urine, and you are feeling crappy.
Anal play (including unprotected anal intercourse) is one of the factors that are really likely to increase your exposure to E. coli.
Even though men are much less likely to get a UTI after sex, those who engage in anal sex increase their chances of getting one, so a condom may be in their best interest.
Do you have a clear plan to beat UTIs?
#4 Contraception increases your chances to contract a UTI
This being said, if you are using condoms with spermicide (or any other Nonoxynol-9 contraception products) for vaginal sex, you could be changing your vagina’s normal microbial balance for the worse.
There are several factors that could predispose you to UTI after sex:
- Lube with glycerin or sorbitol. Buy water-based instead.
- Condoms with spermicide. Buy non-lubricated instead.
- Any Nonoxynol-9 spermicide products (foam, sponge, film)
- Using an IUD for over a year
- Certain hormonal contraceptives
This could also happen if you are stressed out, taking hormones, or have just finished a cycle of antibiotics, as antibiotics kill all bacteria, good and bad, throwing your vaginal flora out of balance.
All these factors may adversely impact the ability of your vagina to ward off E. coli: the more E. coli colonizing your vagina, the easier for the bacteria to get to your urethra.
#5 Other UTI risk factors
Sex increases the chances of contracting a UTI, but there are many other risk factors as well. If you are not sure how you got your UTI, check out 26 main UTI causes that you should know about.
Because bacteria can easily find their way into a woman’s very short (compared to men) urethra, it’s very common for women to have UTIs without knowing the real cause.
Sometimes, the urethra gets irritated by sexual activity and you might then get urinary symptoms like frequency, urgency, and burning while urinating. This is called “honeymoon cystitis,” which may be one of two things. Sometimes after not having any sex for a long time, the vaginal flora may be thrown out of balance chemically (yes, sperm has a chemical makeup), increasing your risk of UTIs (especially if your vaginal immune system is already weakened)- some studies show increased bacteria in the urine after intercourse. Alternately, you could have “honeymoon urethritis.” In this case, the symptoms may not be caused by bacteria or STDs, but by overstimulation and inflammation in the urethra and will likely go away in a few days.
If you repeatedly experience these symptoms and your urine sample is clean, use a lubricant, stay away from spermicides, harsh soaps or other chemicals and make sure your partner is gentle during sex and takes good care of their nails.
How E. coli Can Travel To Your Urethra
It’s pretty natural for E.coli to ascend toward your urethra, but some habits may promote infection with the pathogenic bacteria. (Note: some of these mechanisms have not been proven scientifically, but it can’t hurt to practice caution.)
- Wiping from back to front: The more you expose your genitals to fecal matter (poop!) the higher the chances to infect yourself. Wipe front to back instead.
- Toilet water backsplash. Stay away from it.
- Using a bidet that sprays water from back to front. Use the one with a de-attachable handle instead.
- Wearing thongs: Some believe that wearing thongs promote spreading bacteria from your anus toward your vaginal opening. Wear breathable cotton underwear instead.
- Lastly, UTIs can also be caused by sexually transmitted diseases (STDs) like gonorrhea or chlamydia. When a UTI is caused by an STD, the infection is most often only in the urethra, not the bladder. However, the symptoms are often similar and difficult to distinguish. If you don’t have a UTI and think it may be an STD, get tested.
In closing, remember:
- E. coli is a part of normal bacterial flora in the intestines, rectum, and human poop.
- It is easy for E. coli to travel to your vaginal opening. From there, especially during sex-play, E.coli can travel toward your urethra.
- E. coli normally cannot survive in the healthy vagina for too long (too acidic for its taste). But are pretty happy residing in the urethra and bladder.
- You can use special probiotics to help keep your vaginal flora in balance.
8 Holistic Strategies To Heal And Stop UTI Forever
Chronic UTI is a very misleading diagnosis. Most likely, you need to look for the underlying cause that allows for UTIs to keep happening.
- Heal your bladder
- Fight bacterial biofilms
- Restore healthy gut flora with probiotics
- Improve your diet with a variety of fiber and prebiotics
- Improve your vaginal flora
- Heal your vagina
- Improve emotional health
Written by Anastasia Visotsky, medically reviewed by Dr. Ogunyemi