A douche is a method of rinsing or cleaning out the vagina by squirting water or other solutions into it. A few of the reasons that women give for douching include reducing odors, avoiding sexually transmitted diseases (STDs), and rinsing away blood after a menstrual period. However, healthcare providers don't recommend the practice. A douche changes the delicate chemical balance in the vagina, which can make a woman more prone to bacterial infections or problems with getting pregnant.