Vaginal discharge

In women of reproductive age, the commonest causes of vaginal discharge can be categorised thus:

Infective: non-sexually transmitted

  • Bacterial vaginosis
  • Candida

Infective: sexually transmitted

  • Chlamydia trachomatis
  • Gonorrhoea
  • Trichomonas
  • Herpes simplex (occasional, when the herpes has caused cervicitis)


  • Foreign bodies (e.g. retained tampons, condoms)
  • Cervical polyps
  • Cervical ectopy
  • Genital malignancy
  • Fistulae
  • Allergic reactions


Symptoms of upper genital tract infection

  • Abnormal vaginal bleeding (heavy, intermenstrual, postcoital)
  • Deep dyspareunia
  • Pelvic/abdo pain
  • Fever

If these are present, see BASHH guidelines on PID.

Examination is not always necessary; in a woman at low risk of STI with no symptoms suggestive of upper genital tract infection whose history suggests candidiasis or BV, it is reasonable to treat empirically without examination and advise women to come back for examination if symptoms persist/recur. However, examination should nevertheless be offered.

pH testing can be helpful – collect discharge from lateral walls of vagina using loop or swab and use narrow-range pH paper (4 – 7). Normal vaginal pH is <4.5 and the pH in candida will also be in this range; a pH greater than 4.5 suggests BV or TV.

If STI testing is indicated, do chlamydia/gonorrhoea swabs (for some reason the guideline says endocervical swabs, which seems a bit odd to me as we’ve been using LVSs for NAAT for years now).TV can be tested for with an HVS from the posterior fornix, but motility reduces with transit time and therefore sensitivity can be low; referral to an STI clinic is likely to be the way to go if TV is suspected.

Situations where HVS is recommended are:

  • When symptoms/signs/pH are inconsistent with a specific diagnosis
  • Pregnancy, postpartum, post-abortion or post-instrumentation
  • Symptoms that recur or that persist after treatment.


Bacterial vaginosis

This is the commonest cause of abnormal vaginal discharge in women of reproductive age. While it is not an STI in the true sense, it is now thought to be sexually associated, and seems to occur only in women who have some sexual experience, although this may be oral or digital sex; multiple sex partners increase the risk. It’s also seemingly the one infection for which gay women are more at risk than straight women.

Copper IUCDs also increase the risk of BV. Oral contraceptives and condoms reduce it; Nexplanon and DMPA may also do so.

There is some evidence that the chance of getting BV may be reduced by condom use, although this may only be in women who haven’t had it.

Interestingly, although treating male partners doesn’t seem to be effective in preventing recurrence, treating female partners may be. (However, this seems to be theoretical only, based on high concordance rates of vaginal flora amongst monogamous gay women.)

Treatment can be with metronidazole or clindamycin, either vaginally or orally. All appear to have similar effectiveness, but oral clindamycin has been associated with pseudomembranous colitis and vaginal treatments are more expensive, so oral metronidazole is recommended first-line treatment. SEs include metallic taste and gastrointestinal symptoms. Do note that clindamycin cream can weaken condoms.

BV detected in pregnancy should be treated (it’s associated with premature birth), although there is no evidence to support screening for it. Treatment in pregnancy should be metronidazole 400 mg bd for 5 – 7 days, or vaginal treatment; one-off high doses of metronidazole are not recommended in pregnancy (or in breastfeeding).

Acidifying gels may help prevent recurrence. There is limited evidence for their effectiveness in treatment.

There is little evidence on optimum treatment of recurrent BV. One RCT showed that a 16-week course of twice-weekly metronidazole gel worked better than placebo at prevention for the first twelve weeks after the trial had finished, but the effect wore off after that, and it also increased the risk of thrush.



Also very common; approximately 10 – 20% women have vulvovaginal colonisation with thrush, although many of these won’t be symptomatic and asymptomatic thrush does not require any treatment. It can occur in women with no sexual experience.

It is not linked to use of towels/tampons/panty liners. It isn’t totally clear whether copper IUCDs, contraceptive rings, or oral contraceptives increase the risk; however, DMPA seems to reduce it.

Oral and vaginal single-dose azole treatments are equally effective, so treatment in non-pregnant women can depend upon preference (and also upon contraception, as the vaginal azole creams can damage latex methods). The practice I was taught of prescribing concurrent topical vulval cream for women with vulval symptoms actually has no real evidence to support it; emollients may work just as well with less chance of local irritation as a side-effect. In pregnancy, courses of up to 7 days may work better than a single-dose course.


Trichomonas vaginalis

Offensive yellow frothy discharge which may be scanty or profuse and can be associated with itching, dysuria, and lower abdominal pain. Examination may show visible vulvitis, vaginitis, and/or cervicitis (the cervix may resemble the surface of a strawberry).

Metronidazole (or tinidazole) is effective orally, less so as a vaginal treatment. It can be given either as a course or a single high dose, but the latter is more likely to cause side-effects, is not recommended in pregnant or breastfeeding women, and may be less effective in women with HIV.

Partners should be treated. Test of cure is not required unless symptoms persist.


Cervical ectopy

While it’s possible to treat this with laser, cold coagulation, etc., the evidence base for the effectiveness of these treatments in reducing discharge is limited, and the discharge is likely to get worse before it gets better following treatment.


(CEU guidance, from FSRH webpage)

Test questions

1 – T  2 – F  3 – T  4 – F  5 – F  6 – F  7 – T  8 – T  9 – T  10 – F

(Marked: all correct, though I admit 3 was an educated guess.)


About Dr Sarah

I'm a GP with a husband and two young children.
This entry was posted in Credits 2016, Gynaecology, Sexual health. Bookmark the permalink.

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