Under normal circumstances, there are certain bacteria in the vagina, mainly Lactobacillus vaginalis, which keeps the vagina acidic. This environment is self-purifying and prevents the invasion of external bacteria, which is called the self-purification of the vagina. If the vaginal flora environment changes, such as the reduction of lactobacillus, the amount of other bacteria increased, the normal flora in the vagina is out of order, there will be an increase in leukorrhea, odor, vulvar itching phenomenon, which is often referred to as bacterial vaginosis, in fact, is also the vaginal flora dysfunction of a performance. When this situation occurs, women can take oral metronidazole for treatment, or vaginal metronidazole suppositories for treatment.