What causes frequent urinary tract infections?

Two common causes: Frequent utis in adults especially in women are often related to sexual activities and personal susceptibility.

Many causes: 1) going to sleep with a full bladder after sex, instead of urinating first 2) toilet hygiene: not wiping front to back + trapping urine in vagina with voiding by keeping thighs togther rather than spreading them apart 3) baths and bubble-bath rather thjan showering 4) constipation 5) wearing thongs 6) witholding and long intervaks between urination 7) pregnancy 8) poor diet 9) morbid obesity.