Bacterial vaginosis, or BV, happens when the usual healthy balance in the vagina is upset, leaving a thin grey fluid and a fishy smell. Antibiotics for bacterial vaginosis treat most episodes, usually as a week of tablets or a few nights of a vaginal treatment. This guide explains how antibiotics for bacterial vaginosis are chosen, why BV often comes back, and when to see a doctor.
Key takeaways
- BV is common and is not classed as a sexually transmitted infection, though it is linked to sex.
- The main signs are a thin grey or white fluid and a fishy smell, often stronger after sex.
- A short antibiotic course treats most episodes, but BV comes back for many women within months.
- A Medio doctor can talk it through by phone and arrange a swab test where needed.
What Bacterial Vaginosis Is
Bacterial vaginosis is the most common cause of unusual vaginal fluid in women of childbearing age. It is an imbalance rather than an infection caught from someone: protective lactobacilli drop and other bacteria, such as Gardnerella, multiply. It is not dangerous in itself, but it is uncomfortable and tends to recur.
| Feature | Bacterial vaginosis | Thrush |
|---|---|---|
| Cause | Too few protective bacteria and too many others | An overgrowth of yeast |
| Discharge | Thin and watery, white or grey | Thick and white, like cottage cheese |
| Smell | Fishy, often stronger after sex | Usually none |
| Itch or soreness | Uncommon | Common |
| Usual treatment | Antibiotic tablets, gel or cream | Antifungal cream, pessary or tablet |
Antibiotics for bacterial vaginosis do nothing for thrush, and antifungals do nothing for BV, so the right test matters when the signs are unclear.
Symptoms of Bacterial Vaginosis
The symptoms of bacterial vaginosis are usually a thin, watery discharge that is white or grey, and a fishy smell that is often stronger after sex or during a period. The smell comes from chemicals made by the bacteria that take over. Itching, soreness or burning are less typical and point more towards thrush or an STI.
Up to half of women with BV have no symptoms at all and find out only from a test. When symptoms do appear, they can come and go with the menstrual cycle, and some women first notice them after a new sexual partner.
A pharmacy gel that makes the vagina more acidic can ease the smell for a while, but it is not one of the antibiotics for bacterial vaginosis, and the evidence that it clears the problem is limited. If the symptoms keep returning, see a doctor rather than buying more.
What Upsets the Vaginal Bacteria Balance
The vaginal balance tips towards BV when the vagina becomes less acidic and its protective lactobacilli fall away. Common triggers are a new sexual partner or more than one partner, sex without condoms, and semen, which is alkaline. Douching, vaginal washes, vaginal deodorants and bubble baths strip away the natural protection of the vaginal lining. Menstrual blood raises vaginal pH for a few days each month, and smoking and a copper IUD are also linked to BV. Women who have sex with women can pass it between them through shared vaginal fluid. BV is not caused by poor hygiene, toilet seats or swimming pools, and more washing makes it worse rather than better. Antibiotics for bacterial vaginosis treat an episode, but these triggers decide whether the vaginal balance holds afterwards.
Managing Repeat Episodes After Treatment
BV comes back for more than half of women within a year of treatment, often within a few months. If the fishy smell or vaginal discharge returns, see a doctor rather than treating it yourself, because the discharge may have another cause. For repeat episodes, a doctor may suggest a longer course, or metronidazole gel used twice a week for several months to keep BV away; metronidazole is only available on prescription in Australia. Treating a regular male partner at the same time can also lower the chance of it returning. Keep a note of when symptoms return, such as after a period or a new partner, as the pattern helps the doctor choose.
Everyday Habits That Lower Your Risk
Simple habits lower the chance of BV starting or returning, especially after a bacterial vaginosis antibiotic course ends. Wash the vulva with plain water or a mild soap-free wash, and avoid douching, vaginal steaming, scented washes and deodorants. Use condoms with new partners, and stop smoking if you smoke. If you are taking metronidazole, finish every dose even once the smell goes, because stopping early is a common reason BV comes back. Changing out of wet swimwear and sweaty gym clothes is sensible, though the evidence for underwear choices is weak. A change in vaginal discharge after a new partner is a reason for an STI test as well, because some infections cause a similar discharge.
When to Seek Care, Including During Pregnancy
See a doctor the first time you notice signs of BV, so it can be told apart from thrush and STIs, and whenever it returns after treatment. During pregnancy, BV is linked to a higher chance of early labour, so pregnant women with signs should tell their doctor or midwife promptly; some treatments, including metronidazole tablets, are used in pregnancy, and the doctor chooses which. See a doctor soon, in person if needed, for pain low in the tummy, fever, bleeding between periods or after sex, or sores, as these suggest something other than BV. Seek care too if the signs have not settled a week after a bacterial vaginosis antibiotic course. For severe pain with fever, or if you feel very unwell, call 000 or go to an emergency department.
How a Doctor Confirms Bacterial Vaginosis
Bacterial vaginosis is diagnosed by a doctor from what you describe and a swab. In a clinic, the doctor may look at the vaginal discharge, test its pH and check a sample under a microscope. More often a swab, which you can usually collect yourself, goes to a laboratory, and the result shows whether BV, thrush or trichomoniasis is behind it. STI tests are often done at the same time.
By phone, in a telehealth consult, there is no examination, so a Medio doctor asks about the signs, your sexual health and any pregnancy, and can send a pathology request for a self-collected swab. Where the picture is typical of BV, the doctor may treat without waiting for the result.
Treatment for bacterial vaginosis is a course of antibiotics, as tablets or a vaginal gel or cream, and BV is treated the same way when it returns. Related treatments, such as acidic gels and probiotics, have weaker evidence and do not replace a course. What causes bacterial vaginosis matters here too: if a trigger keeps returning, the doctor talks it through. Bacterial vaginosis in pregnancy is treated when it causes signs, with a course suited to pregnancy.
Summary
Bacterial vaginosis is common and treatable, and antibiotics for bacterial vaginosis treat most episodes, though it often returns. This guide covered its signs, triggers, repeat episodes, everyday habits, pregnancy and testing. If you think you have it, a Medio doctor can assess you by phone, talk through antibiotics for bacterial vaginosis and, where the doctor thinks it right, send a pathology request, an eScript or a referral.
Frequently asked questions
What antibiotic works best for BV?
No single antibiotic suits everyone. Australian guidelines usually start with metronidazole tablets twice a day for seven days, and a vaginal treatment is an alternative; metronidazole is only available on prescription in Australia. The doctor chooses by pregnancy, allergies, past episodes and what you prefer.
What should you know about management of sex partners?
Treating a regular male partner at the same time lowers the chance of BV coming back, recent Australian research found, and some sexual health services now offer it, with tablets and a cream for the partner. A female partner with signs should be checked too. Other management considerations include using condoms until you have both finished treatment.
Can a doctor help with antibiotics for bacterial vaginosis?
A Medio doctor can help by phone: they can assess your signs, arrange a swab through a pathology request if needed and, where the doctor thinks treatment is right, send an eScript. A first episode in pregnancy, or pelvic pain, may need a visit in person.
What should you know about further reading on bacterial vaginosis?
Reliable further reading on bacterial vaginosis comes from Australian government health information, state sexual health services and women's health organisations, which keep their advice in line with local guidelines. Be wary of sites selling cures or products. Your doctor or a sexual health clinic can point you to good sources.
What should you know about sexual health clinics can help with bacterial vaginosis?
Sexual health clinics can help with bacterial vaginosis: public clinics in each state test and treat BV and STIs, usually free and confidentially, and some do not need a Medicare card. Many also offer partner treatment and advice on repeat episodes. You can also see your GP, or speak with a Medio doctor by phone.
Can you clear BV in 3 days?
No reliable treatment clears BV in 3 days. The usual tablet course runs for seven days and a vaginal gel for five nights. The smell often eases within a few days, but stopping early makes BV more likely to return, so finish the whole course.
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