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    Tests for Bacterial Vaginosis

    How To Prepare

    Do not douche, have sex, or use vaginal medicines for 24 hours before having a bacterial vaginosis test.

    Talk to your doctor about any concerns you have regarding the need for the test, its risks, how it will be done, or what the results will mean. To help you understand the importance of this test, fill out the medical test information form(What is a PDF document?).

    How It Is Done

    You will take off your clothes below the waist. You will have a gown to drape around your waist. You will then lie on your back on an examination table with your feet raised and supported by stirrups. This is similar to having a pelvic examination camera.gif or Pap test.

    Your doctor will insert a lubricated tool called a speculum camera.gif into your vagina. The speculum gently spreads apart the vaginal walls, allowing your doctor to see the inside of the vagina and the cervix.

    Samples of fluid inside the vagina are then collected with a swab or wooden stick.

    How It Feels

    You may feel some discomfort when the speculum is put in, especially if your vagina is irritated and tender.


    There is little or no risk in having a bacterial vaginosis test.


    Tests for bacterial vaginosis take samples of fluid and cells from the vagina to see if signs of infection are present.

    A high vaginal pH, clue cells, and a fishy odor are some signs that bacterial vaginosis is present.

    Tests for bacterial vaginosis

    No abnormal vaginal discharge is present on vaginal exam.

    A wet mount does not show large numbers of bacteria, such as Gardnerella, that cause bacterial vaginosis.

    Few or no clue cells are present.

    No fishy odor is present when a potassium hydroxide (KOH) solution is added to a sample of vaginal discharge.

    Vaginal pH is in the normal range of 3.8 to 4.5.


    A bacterial vaginosis infection is present.

    • A thin, grayish white vaginal discharge is present on vaginal exam. The discharge often looks shiny and has small bubbles.
    • A fishy odor is made when a KOH solution is added to a sample of vaginal discharge.
    • Large numbers of the types of bacteria that cause bacterial vaginosis (such as Gardnerella), clue cells, or both are present on wet mount.
    • Vaginal pH is greater than 4.5.

    WebMD Medical Reference from Healthwise

    Last Updated: March 12, 2014
    This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

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