Recurrent bacterial vaginosis: why it keeps coming back

A recurring case of bacterial vaginosis is by no means exceptional.

It is actually one of the most common patterns in intimate health, and yet one of the least well explained.

Treatment followed, symptoms gone, then another episode a few weeks later: many women experience this cycle without ever really understanding why.

The good news is that this is neither a coincidence, nor a matter of poor hygiene.

It is a documented biological phenomenon, with identifiable mechanisms, and concrete actions to get out of it.

What is bacterial vaginosis?

Bacterial vaginosis is the most common imbalance of the vaginal microbiome in women of childbearing age.

Unlike a classic infection, it is not caused by an external germ that "attacks" the body.

It occurs when lactobacilli, which are normally in the majority in the vagina, give way to anaerobic bacteria such as Gardnerella vaginalis.

This shift modifies the vaginal pH, which is usually acidic thanks to what is called the Döderlein flora.

In practice, this often results in thin, greyish or yellowish discharge with a distinct odour, which can sometimes be more noticeable after sex.

But in nearly half of all cases, BV causes no visible symptoms, which complicates the situation even further: it is impossible to know that the balance has changed without paying close attention.

Why does BV recur so often?

Even when properly treated, bacterial vaginosis frequently recurs.

This is neither a coincidence, nor a treatment failure: no current antibiotic is able to completely eliminate the biofilm formed by the bacteria involved, which largely explains the frequency of recurrences, as the Merck Manual points out.

Several factors can also trigger a new episode.

Excessive intimate hygiene

Paradoxically, wanting to "do the right thing" can work against you.

Douching, scented soaps, washcloths: anything that strips away the natural protective film opens the door to imbalance.

External intimate washing, once or twice a day maximum, with a cleanser adapted to physiological pH, remains the most solid foundation for limiting recurrences.

Antibiotics

This is one of the most frustrating paradoxes of BV: the treatment meant to get rid of it can also weaken the vaginal flora and encourage... another episode later on.

Hormonal variations of the cycle

As with thrush before periods, the hormonal cycle directly influences vaginal balance.

Progesterone and oestrogen act on the composition of the vaginal environment, and these fluctuations can be enough to disrupt an already fragile balance, particularly during the premenstrual phase or during menopause.

When is BV considered "recurrent"?

The medical threshold generally used is this: the current episode, associated with at least two previous episodes occurring within the preceding 12 months.

If this is where you are, it is no longer really an isolated "stroke of bad luck", but a pattern that is worth taking seriously with a healthcare professional.

In this case, specific management may be considered, differing from standard treatment: a prolonged suppressive treatment, for example using vaginal metronidazole over several weeks, may be suggested by your doctor in case of frequent recurrences.

BV or thrush: how to tell the difference?

This is often where the vicious circle truly sets in.

The symptoms of BV and those of vulval irritation or thrush can look identical, yet their treatments are completely different: antibiotics for BV, antifungals for thrush.

Using the wrong treatment means prolonging discomfort, sometimes masking the real problem, and often feeding into the next recurrence.

A few pointers can help to tell them apart:

• BV most often causes thin, greyish discharge with a distinct odour, but rarely severe itching.

• Thrush is more likely to present with intense itching, thick discharge, and an absence of any strong odour.

• In both cases, self-diagnosis based solely on observation remains risky: symptoms alone are not always enough to decide.

Practical steps to limit recurrences

There is no single solution, but several actions, combined, make a real difference.

Adapting your intimate hygiene routine. A gentle external wash, once a day, with a pH-neutral product. No douching, ever.

Reviewing your contraception if it is the cause. Some methods disrupt the flora more than others; speaking with a healthcare professional sometimes allows you to adjust what does not suit you.

Considering a course of vaginal probiotics. Several studies suggest a real benefit in helping to restore and maintain the balance of the flora after an episode.

Involving your partner. It is not always an obvious instinct, but it is sometimes the missing piece of the puzzle, especially in cases of closely spaced recurrences.

Avoiding repeated self-medication without confirmation. Taking the same treatment for every symptom, without checking what is really going on, can delay the identification of the true pattern at play.

How to know if it is a new case of vaginosis or something else?

You never really know, from one episode to the next, whether it is a new case of BV, thrush, or something else. You hesitate between waiting, booking an urgent appointment, or trying the same treatment as last time.

This is exactly the gap that the Santelle vaginal test was designed to fill.

Carried out at home in about ten minutes, it analyses several vaginal environment biomarkers, including pH, to give you concrete indications of what is really going on, and to help you decide, with full knowledge of the facts, whether it is necessary to consult a professional.

The app that accompanies the test also allows you to keep track of your results over time, which is particularly useful in case of recurrences: identifying a repeating pattern is often the first step to breaking it.

The test does not replace a medical diagnosis, it will never tell you "it is definitely BV" with the certainty of a consultation. But it gives you the means to stop navigating blindly between appointments.

When to consult without delay

Certain signs should prompt you to make an appointment without delay, even outside of an established recurring pattern:

• marked pelvic pain or fever,

• unusual bleeding,

• an ongoing pregnancy,

• symptoms that persist beyond a week despite treatment,

• or, indeed, episodes that recur at short intervals.

According to the WHO, bacterial vaginosis remains the most common gynaecological condition among women of childbearing age globally — which also means there is wide and well-established medical expertise to manage it, including in its recurring forms.

A pharmacist can also be a useful first point of contact, particularly if you are hesitating between several possibilities or wish to be guided before consulting a doctor.

External sources cited: WHO – Bacterial vaginosis · MSD Manuals, Consumer Version