2018 European (IUSTI/WHO) International Union against sexually transmitted infections (IUSTI) World Health Organisation (WHO) guideline on the management of vaginal discharge:

Four common pathological conditions are associated with vaginal discharge: bacterial vaginosis, aerobic vaginitis, candidosis, and the sexually transmitted infection, trichomoniasis. Chlamydial or gonococcal cervical infection may result in vaginal discharge. Vaginal discharge may be caused by a range of other physiological and pathological conditions including atrophic vaginitis, desquamative inflammatory vaginitis, cervicitis, and mucoid ectopy. Psychosexual problems may present with recurrent episodes of vaginal discharge and vulval burning. These need to be considered if tests for specific infections are negative. Many of the symptoms and signs are non-specific and a number of women may have other conditions such as vulval dermatoses or allergic and irritant reactions.