# Why do we wash our hands after going to the bathroom? **URL:** \ **Category:** Factual Questions\ **Created:** [June 30, 2010, 10:28pm UTC](https://boards.straightdope.com/t/why-do-we-wash-our-hands-after-going-to-the-bathroom/545130 "2010-06-30T22:28:57Z")\ **Posts on this page:** 9\ **Page:** 2
**Author:** ![Leaffan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leaffan/32/299_2.png) [@Leaffan](https://boards.straightdope.com/u/Leaffan)\ **Post date:** [July 1, 2010, 4:45pm UTC](https://boards.straightdope.com/t/why-do-we-wash-our-hands-after-going-to-the-bathroom/545130/21 "2010-07-01T16:45:43Z")
Because Mum told me to. ---
**Author:** ![Chief\_Pedant](https://avatars.discourse-cdn.com/v4/letter/c/a6a055/32.png) [@Chief\_Pedant](https://boards.straightdope.com/u/Chief_Pedant)\ **Post date:** [July 1, 2010, 5:20pm UTC](https://boards.straightdope.com/t/why-do-we-wash-our-hands-after-going-to-the-bathroom/545130/22 "2010-07-01T17:20:08Z")
> [@gallan](#): > > This makes perfect sense to me! I hadn’t really considered it a convenience thing. Thanks! Sadly, the good doctor’s explanation was completely ass-backward–literally. You see, any pathogens you are pooping out already made it past the “oral” part of the fecal-oral cycle. It’s the OTHER guy’s feces that might contain pathogens for you; if your own feces contains pathogens you are already infected and it’s too late. Feel entirely free, medically-speaking, to munch your own fe…never mind; the thought is disgusting. Reminds me why I don’t like babies. In any case it is absolutely impossible to avoid the bacteria you carry around on and in your own body. On edit: perhaps I read it too fast. If the good doctor is saying frequent hand washing avoids contamination from others…well; kinda. But it would have to be pretty darn OCD-level frequency. It’s really not very practical, although certainly a given public toilet, frequently-used enough to have viable bacteria everywhere, is a reasonable motivation to wash in case any pathogens were left by its filthy previous users. ---
**Author:** ![Darth\_Panda](https://avatars.discourse-cdn.com/v4/letter/d/ee7513/32.png) [@Darth\_Panda](https://boards.straightdope.com/u/Darth_Panda)\ **Post date:** [July 1, 2010, 5:24pm UTC](https://boards.straightdope.com/t/why-do-we-wash-our-hands-after-going-to-the-bathroom/545130/23 "2010-07-01T17:24:55Z")
> [@Chief\_Pedant](#): > > Now the hooker is that there are some pathogenic germs out there, the transmission of which will be diminished by good hygiene. Hooker? ---
**Author:** ![Chessic\_Sense](https://avatars.discourse-cdn.com/v4/letter/c/7c8e57/32.png) [@Chessic\_Sense](https://boards.straightdope.com/u/Chessic_Sense)\ **Post date:** [July 1, 2010, 6:14pm UTC](https://boards.straightdope.com/t/why-do-we-wash-our-hands-after-going-to-the-bathroom/545130/24 "2010-07-01T18:14:11Z")
> [@Chief\_Pedant](#): > > You see, any pathogens you are pooping out already made it past the “oral” part of the fecal-oral cycle. It’s the OTHER guy’s feces that might contain pathogens for you; if your own feces contains pathogens you are already infected and it’s too late. I feel I need to post this semi-NSFW [video](http://www.imdb.com/video/imdb/vi4206561049/). ---
**Author:** ![Acsenray](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/acsenray/32/4519_2.png) [@Acsenray](https://boards.straightdope.com/u/Acsenray)\ **Post date:** [July 4, 2010, 4:22am UTC](https://boards.straightdope.com/t/why-do-we-wash-our-hands-after-going-to-the-bathroom/545130/25 "2010-07-04T04:22:52Z")
> [@gallan](#): > > Seriously, why is hand-washing after using the bathroom such a big deal? I’m not in the habit of getting urine or poop on my hands … don’t? If you use toilet paper to clean your backside after defecation then you definitely have poop on your hand, even if you can’t see or smell it. ---
**Author:** ![elelle](https://avatars.discourse-cdn.com/v4/letter/e/f0a364/32.png) [@elelle](https://boards.straightdope.com/u/elelle)\ **Post date:** [July 4, 2010, 6:01am UTC](https://boards.straightdope.com/t/why-do-we-wash-our-hands-after-going-to-the-bathroom/545130/26 "2010-07-04T06:01:55Z")
I’ll summon up the ol’ ghost of Ignatz Semmelweis, who really didn’t get enough credit in his [own lifetime](http://en.wikipedia.org/wiki/Ignaz_Semmelweis) with hand-washing hygiene, and had to fend for his very rational observance of bodily contamination against the mores of the day. Really, read the whole Wiki article, it’s worth it. > [@](#): > > (from above source):He concluded that he and the medical students carried “cadaverous particles” on their hands[Note 6] from the autopsy room to the patients they examined in the First Obstetrical Clinic. This explained why the student midwives in the Second Clinic, who were not engaged in autopsies and had no contact with corpses, saw a much lower mortality rate. > The germ theory of disease had not yet been developed at the time. Thus, Semmelweis concluded that some unknown “cadaverous material” caused childbed fever. He instituted a policy of using a solution of chlorinated lime (modern calcium hypochlorite, the compound used in today’s common household chlorine bleach solution) for washing hands between autopsy work and the examination of patients. He did this because he found that this chlorinated solution worked best to remove the putrid smell of infected autopsy tissue, and thus perhaps destroying the causal “poisonous” or contaminating “cadaveric” agent hypothetically being transmitted by this material. > The result was that the mortality rate dropped ten-fold, comparable to the Second Clinic’s. The mortality rate in April 1847 was 18.3%; after handwashing was instituted in mid-May, the rates in June were 2.2% July 1.2%, August 1.9% and, for the first time since the introduction of anatomical orientation, the death rate was zero in two months in the year following this discovery. > [@](#): > > (same source)work offered a theoretical explanation for Semmelweis’s observations—the germ theory of disease. As such, the Semmelweis story is often used in university courses with epistemology content, e.g. philosophy of science courses—demonstrating the virtues of empiricism or positivism and providing a historical account of which types of knowledge count as scientific (and thus accepted) knowledge, and which do not. It is an irony that Semmelweis’s critics considered themselves positivists. They could not accept his ideas of minuscule and largely invisible amounts of decaying organic matter as a cause of every case of childbed fever. To them, Semmelweis seemed to be reverting to the speculative theories of earlier decades that were so repugnant to his positivist contemporaries. > The so-called Semmelweis reflex — a metaphor for a certain type of human behaviour characterized by reflex-like rejection of new knowledge because it contradicts entrenched norms, beliefs or paradigms — is named after Semmelweis, whose perfectly reasonable hand-washing suggestions were ridiculed and rejected by his contemporaries. Those ideas were radical for the time, but are accepted as sound now. And, since it’s been a relatively recent development, only a hunnert and fifty years or so, right, I’d expect we’re right what we should be paying real attention as a group. ---
**Author:** ![Lynn\_Bodoni](https://avatars.discourse-cdn.com/v4/letter/l/e47c2d/32.png) [@Lynn\_Bodoni](https://boards.straightdope.com/u/Lynn_Bodoni)\ **Post date:** [July 4, 2010, 9:03am UTC](https://boards.straightdope.com/t/why-do-we-wash-our-hands-after-going-to-the-bathroom/545130/27 "2010-07-04T09:03:13Z")
> [@DrFidelius](#): > > If you are a chemist, you wash your hands before you go. > [@Ludovic](#): > > Or if you cook with habaneros. Unless you’ve already gotten past that barrier already and certain parts are almost as numb to capsaicin as your taste buds :eek: > > Not that I’m referring to anyone there…🆒 It was a [jalapeño](http://boards.straightdope.com/sdmb/showthread.php?t=563468), if you’re thinking about the thread I’m thinking about. ---
**Author:** ![Ludovic](https://avatars.discourse-cdn.com/v4/letter/l/7ab992/32.png) [@Ludovic](https://boards.straightdope.com/u/Ludovic)\ **Post date:** [July 4, 2010, 1:38pm UTC](https://boards.straightdope.com/t/why-do-we-wash-our-hands-after-going-to-the-bathroom/545130/28 "2010-07-04T13:38:49Z")
Nope, it’s my own hard-won knowledge. I told you I was hardcore! ---
**Author:** ![UltraVires](https://avatars.discourse-cdn.com/v4/letter/u/ecccb3/32.png) [@UltraVires](https://boards.straightdope.com/u/UltraVires)\ **Post date:** [July 4, 2010, 5:57pm UTC](https://boards.straightdope.com/t/why-do-we-wash-our-hands-after-going-to-the-bathroom/545130/29 "2010-07-04T17:57:55Z")
You know when I wash my hands? When I shit on them. And that happens two to three times a week. Tops!–George Carlin [Previous page](https://boards.straightdope.com/t/why-do-we-wash-our-hands-after-going-to-the-bathroom/545130.md?page=1)