Bacterial Vaginosis (BV)

This webpage is for information purposes only and is not a substitute for professional medical advice.

Many different bacteria, most from the lactobacillus family, live harmlessly in the vagina and help keep it mildly acidic. Bacterial vaginosis (BV) results when these “good” bacteria are replaced by an overgrowth of other types of bacteria such as gardnerella. (Bacterial vaginosis is also known as non-specific vaginitis; bacterial vaginitis or gardnerella.)

While no-one really knows why these levels of bacteria change, research shows that a woman is more likely to be diagnosed with BV if she’s had multiple sex partners, smokes or has an IUD.

Signs & Symptoms

Having gardnerella in your vagina doesn't automatically mean you have BV. In fact, up to 50% of women diagnosed with bacterial vaginosis don't have any symptoms.

Signs and symptoms of BV include:

  • An unpleasant "fishy" odour that's especially noticeable after sex without a condom.
  • A white (or grey), thin vaginal discharge (sometimes in large amounts).
  • Pain, burning or itching in the vagina during intercourse. (This may occur, but isn't common.)

Diagnoses & Treatment


Your doctor will do a pelvic exam to look for a white, thin coating on your vaginal walls. Then he or she will take a swab sample from your vagina. The sample will be sent to a lab for a pH test and to see if any microscopic “clue cells” (vaginal skin cells that are coated with bacteria) are visible.


Flagyl® (metronidazole) is the most effective treatment for BV. Your doctor will prescribe either pills or a cream. Anti-fungal creams and suppositories (ovules) for yeast infections don't work for bacterial vaginosis.

You must be treated if:

  • You're having definite symptoms of BV.
  • You’re having pelvic surgery in the near future.
  • You’re pregnant. (Bacterial vaginosis often occurs during pregnancy. It can cause premature labour and uterine infections. If you have a history of premature labour or other complications you might be examined for bacterial vaginosis even if you don't have any symptoms.)

You might feel sick to your stomach or have diarrhea while taking Flagyl®. Other side effects include a persistent, dry metallic taste in the mouth and less vaginal lubrication.

Combining alcohol and Flagyl® will cause you to vomit. So don't drink wine, liquor or beer while taking Flagyl® or for 48 hours after finishing treatment.

If you finish your Flagyl® medication and still have symptoms, return to your doctor for more testing and treatment.

If your infection keeps recurring and is hard to treat, consider keeping a diary of your symptoms and your activities. This will help you:

  • Evaluate the amount of discharge and other symptoms.
  • See if there are patterns to recurrences.
  • Associate symptoms with activities e.g., unprotected vaginal sex.


You can reduce your risk of BV and keep your vagina healthy by:

Eating a healthy, balanced diet

Avoiding harsh detergents

  • Don't take bubble baths.
  • Don't use perfumed soaps and feminine hygiene sprays.
  • Don't use strong detergents and fabric softeners when washing underwear.

Practicing hygiene

  • Don't douche. Douching may make BV worse by washing away the "good" bacteria in the vagina.
  • Wash your genitals with only warm water.
  • o Always wash or wipe from front to back, avoiding the spread of bacteria from the anus to the vagina.
  • Rinse  soap away from genitals.
  • Don't put anything in your anus and then into your vagina (without thoroughly cleaning it first).
  • Don't use anyone else's wet towel, washcloth or bathing suit.

Practicing safe sex

  • Always use latex or polyurethane condoms or dental dams when you are engaging in sexual activities.

Watching what you wear

  • Wear cotton underwear and avoid thong underwear for extended periods of time.
  • Don't wear underwear to bed. (Try boxers!)
  • Avoid wearing tight jeans and pants.

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