Downvoted: This is potentially harmful advice if you have a vagina.
The majority of cases of cystitis or urethritis are from E. coli, the normal flora that lives in your gastrointestinal tract. This helps you digest your food, but if you wipe from back to front you risk smearing it to your urethral meatus (pee hole). Then the bacteria get into a sterile environment [your pee hole] and cause a UTI. This was traditionally taught in medical school to be “Honeymoon cystitis” as many women would get UTIs after their vigorous honeymoon weekend and come back with this normal infection. Maybe we see less of this these days with premarital sex and living together.
That feels a bit mis-representatative: There’s no conclusive evidence, but there is weak evidence in favor.
The first doctor says it doesn’t matter, the second says it does, and the three linked studies say (mildly harmful, no effect, no effect), with small sample sizes. The first doctor also explicitly states that he’d still wipe front-to-back if he were female!
I’d call that weak evidence towards harm, i.e. this is potentially harmful advice.
Downvoted: This is potentially harmful advice if you have a vagina.
Source: http://lifehacker.com/5805108/which-direction-should-i-wipe
And the rest of the article says that there is no conclusive evidence either way.
That feels a bit mis-representatative: There’s no conclusive evidence, but there is weak evidence in favor.
The first doctor says it doesn’t matter, the second says it does, and the three linked studies say (mildly harmful, no effect, no effect), with small sample sizes. The first doctor also explicitly states that he’d still wipe front-to-back if he were female!
I’d call that weak evidence towards harm, i.e. this is potentially harmful advice.