Women may be at higher risk of developing a urinary tract infection (UTI) after having sex. This is because the urethra, which is the tube that runs from the bladder to the outside is shorter in a woman than a man. During sex, bacteria can be shifted from around the anus towards the front, and then into the urethra. Passing urine after having sex can help to flush the bacteria out and reduce the chance of developing UTI. You should also remember to always wipe from front to back, and not from back to front, to reduce the chance of spreading bacteria.