I was pissing blood — like I’d eaten beets, except I hadn’t. A tiny demon was sitting in my abdomen, twisting my organs into knots while stabbing them with knitting needles. It wasn’t my period. That was all I knew.

I searched for “pissing blood pain abdomen,” and Google told me I had not just developed a urinary tract infection but that the infection had crawled its way upward and become acute cystitis: a bacterial infection of the bladder that could eventually develop into a kidney infection.

The worst part of it all? I was doing night production for the Daily Cal, and if I left to writhe in pain at home there would be no newspaper the next day. I couldn’t find anyone to cover for me, so I stayed, running to the bathroom every 10 minutes and clutching my abdomen, trying to explain to the only other person in the office, a pre-med night editor, what was happening. He looked confused.

I’d heard about urinary tract infections , or UTIs. I hadn’t heard they could become this severe this soon, but I also hadn’t pissed for nearly 36 hours after having sex. One of the early symptoms is no longer feeling the urge to pee. Meanwhile, bacteria are slowly colonizing the urinary tract and marching toward the kidney to the beat of Chopin’s Funeral March. Thankfully, most UTIs are merely annoying, not debilitating.

Why is it that we hear more about women contracting UTIs than men? And what do these infections tell us about our choices and our bodies, with their complex microbiomes — the microbial ecosystems that populate both our insides and outsides and either keep us healthy or make us piss blood?

First of all, female anatomy explains why female-bodied folks develop UTIs significantly more often than male-bodied ones. There’s a much shorter distance from the urethra to the anus, and E. coli, found in our intestines, causes most infections.There’s also a much shorter distance from the urethral opening to the bladder — that is, our urinary tracts are shorter, so there’s less distance for bacteria to traverse.

In most situations when a young, healthy, sexually active woman develops a UTI, it was easily preventable. Peeing immediately after sex flushes out any bacteria that may be on or near the urethral opening or developing in the urinary tract. Cuddling can wait.

That brings us to the second question: the one about our microbiome. We have 10 times more microorganisms living on and in us at all times than human cells. Although we generally think about microorganisms in terms of the diseases they cause, we don’t yet understand much about the ways in which they keep us healthy.

A relatively young company, AOBiome, now produces an ammonia-oxidizing bacteria spray that repopulates users’ skin with healthy bacteria so they don’t smell bad, even if they never shower again. Ironically, the chemicals we regularly put on our bodies to keep ourselves clean effectively wipe out this skin microbiome. One local writer, Julia Scott, experimented with the AO+ spray for the New York Times Magazine. She confirmed it was as effective as described in published research that found better-balanced skin microbiota decreases eczema and acne and accelerates wound healing, among a number of other benefits.

What if our pursuit for cleanliness is actually costing us our health? Douching used to be recommended by doctors until they realized washing the vaginal canal regularly increased rates of bacterial vaginosis (bacterial infections in the vagina), pelvic inflammatory disorder and cervical cancer. In fact, healthy vaginal biomes are key to preventing urogenital diseases, including UTIs, and douching was destroying helpful microorganisms and stripping vaginas of their natural defenses, paving the way for disease-causing pathogens.

We have a long way to go before we truly understand the complex interplay of disease and human-microbial symbiosis, but even a basic conceptualization of ourselves as biological ecosystems can help us better understand how to take care of ourselves. What we put on and in our bodies and what we do or fail to do with them have far-reaching implications for our health in ways that are invisible to the naked eye (although they might not stay that way). We’re tied into symbiotic relationships with the invisible single-celled creatures inside of us, and our choices about whether to pee after sex or take antibiotics nurture or harm not just our own cells but theirs as well.

Things only got worse after I left the Daily Cal office that night. I drank so much water and cranberry juice and my stomach distended, but at least I stopped pissing blood. It took a few more days before I began to feel normal again and my body stopped demanding I run to the bathroom every few minutes.

I realized our immune systems need all the help they can get. If you learn nothing else today, remember to take care of your microbiota. Do not douche, but do pee right after sex. Your body will thank you.