Bacterial Vaginosis

  • Common vaginal infection
  • Occurs due to imbalance between naturally-occurring good and bad bacteria
  • Primarily affects females

Signs and Symptoms

Many women usually do not have any symptoms.  The women who do experience symptoms may notice a larger than normal amount of discharge from the vagina.  The discharge is a grayish-white colour with a fishy odour, which may be more noticeable after sexual intercourse.


The exact cause of BV remains unclear; however, the infection may be spread during vaginal sex.  Bacterial Vaginosis is responsible for 45% of all infections of the vagina.  It is not considered a sexually transmitted infection, as no woman is immune.  It can also occur in females who have never had sexual intercourse.

There is no male equivalent of bacterial vaginosis.  Males are not treated for this infection, as studies show that treating male partners does not have an influence on whether or not the female will develop bacterial vaginosis again.  Because BV affects primarily females, the infection can be spread between female sexual partners.


On medical examination, the doctor is often able to tell whether or not a woman has BV by looking at the discharge from the vagina.  To confirm his/her findings, the doctor may send a sample of the discharge to the laboratory for testing.

It is important to seek medical advice to rule out similar, but more serious, infections such as trichomonas.

Most men are not routinely tested for bacterial vaginosis.


Bacterial vaginosis usually does not cause complications.  In some cases, BV may be linked to a serious disease known as Pelvic Inflammatory Disease (PID), which causes an infection in the uterus, the fallopian tubes and the ovaries.  If PID develops and is left untreated, it can cause infertility.

Pregnancy:  If a woman is pregnant and has BV, she may have premature labour and deliver a low birth weight baby.

Treatment and Prevention

Although bacterial vaginosis can sometimes be cleared without medication, it is important to seek treatment once you have the infection to reduce the risk of complications.  Treatments usually include antibiotics called metrondiazole (brand name Flagyl) or clindamycin.

WARNING:  Do not drink alcohol when taking metrondiazole.  Alcohol can react with this antibiotic and can cause severe nausea and vomiting.  Alcohol should be avoided for at least two days after treatment has been completed.

Pregnancy:  If a woman is pregnant or nursing, she should consult with her physician regarding the use of metrondiazole.

Despite treatment, re-infection remains possible. If you have had the infection once, you can still become infected.

Medical Follow-up

Once the symptoms have been treated, follow up with your doctor is not needed.

Additional Information

  • Avoid sex while being treated
  • Avoid douching (cleaning the vagina); the vagina does not need cleaning.  Cleaning the vagina can kill off the healthy bacteria and can cause other bacteria to grow out of control and lead to infection
  • Get tested for other infections, as it is possible to be infected with more than one
  • After bowel movements, wipe front to back, away from the vagina, to prevent the spread of bacteria from the bowel
  • Moisture is bacteria’s best friend!  Avoid clothing, such as tight jeans, panty hose without a cotton lining or underwear that are not made of cotton.  All of these can trap moisture and lead to infection

**If you have any type of infection in the genital area, it is important to inform your partner so that they can also be properly examined and treated if need be**  

This information is for general knowledge only and does not replace professional medical advice. For STI testing or more information, contact our confidential sexual health clinic at 519-753-4937 ext. 471.