Answer:
Douche cleansing fluids tend to alter the vaginal pH and this can negatively impact the vagina's normal healthy bacterial flora and mucus and make one more susceptible to infections from yeast or bacteria. Ingredients in douche fluids can be harsh on the sensitive vaginal mucosa and cause chemical irritation. Douching may actually flush vaginal bacteria up into the cervix and uterus causing possibility of cervical or uterine irritation.
External genital cleansing with a gentle soap and a warm water rinse into the vagina is acceptable, and is all you need to clean your female parts.