The most important rule for any sexually active woman is to empty their bladder within 15 minutes of sex. Whether it is same-sex, with a sex toy or heterosexual intercourse, unless you empty your bladder you are more likely to get a urinary tract infection (UTI), which can be very uncomfortable and can lead to bigger problems. The reason that women get UTIs after sex is that the urethra is very short and the bladder is close to it, so during penetrative sex you are allowing bacteria direct access to your bladder.
We don’t know why some people are more susceptible to UTIs than others, but post-menopausal women should be extra-careful, because as a reduction in oestrogen leads to the tissue being thinner, making it harder to fight infection. Even if your partner is a clean person you are still at risk; using a condom or being circumcised doesn’t make a difference. Penetrative sex upsets the natural balance of your body so always make sure to go to the bathroom afterwards.
What women must avoid is douching. Intra-vaginal douching or cleansing disrupts the delicate natural balance of the vaginal bacteria, which maintains a status of health. It reduces the amount of lactobacillus, the bacterium that promotes acid and suppresses the growth of unnatural germs. By attempting to clean your body, you are actually exposing yourself to a higher risk of infection.
For women to whom there is often a desire to feel less “wet” after sex. If this is the case, gentle cleansing of your external genitalia with water is perfectly safe – no scrubbing is required, and avoid harsh soaps. It is a myth that you can “wash away” sexually transmitted infections after sex by showering or douching, so being anticipatory is vital: use a condom.