The presence of bacterial vaginitis is considered when the discharge is yellow after menstruation. Bacterial vaginitis is one of the common vaginal inflammatory diseases in obstetrics and gynecology, caused by dysbiosis of the flora. After menstruation, estrogen and progesterone levels are relatively low and there are fewer dominant bacilli in the vagina, so the pH level in the vagina increases. The vagina itself is less capable of self-cleaning and this, combined with the invasion of exogenous pathogens, makes it prone to bacterial vaginitis. The main clinical manifestations are increased vaginal discharge, yellowing and itching of the vulva due to the irritation of the discharge. The main treatment is metronidazole, which can be taken orally. Generally, two tablets should be taken twice a day after meals to reduce gastrointestinal irritation. You can also consider using metronidazole suppositories inside and outside the vagina, the effect of both treatments is similar.