Metronidazole suppositories are generally recommended to use a course of treatment, if the use of a course of treatment after the effect is not good, it is recommended to go to the hospital under the guidance of the doctor for regular use of medication, there is no so-called longest use of the course of treatment. Metronidazole suppository is a metronidazole preparation, the active ingredient is metronidazole, which can inhibit the growth of anaerobic bacteria at the same time will not inhibit the lactobacillus, so in the clinic is often localized medication used for the treatment of bacterial vaginosis, usually given metronidazole suppository once a night, seven days of continuous use. For the regular use of metronidazole suppositories after a course of treatment, there is still a fishy vaginal discharge and vulvar itching and other discomforts, should not increase the course of treatment, it is recommended to gynecological consultation as soon as possible, under the guidance of the doctor standardized use of medication, so as not to cause adverse reactions, affecting the prognosis of the disease.