Four Classes of STD\'s. BacterialFungusParasitesViruses- NOT curable. BACTERIAL VAGINOSIS. Bacterial Vaginosis. Bacterial infectionYou get it from douching, others believe it is caused by an over growth of bacteria normally found in the vagina.Very Common STD.Symptoms: You may or may not experience symptoms. Known to cause unpleasant fishy odor, sticky, milky thin gray or white vaginal discharge, which causes itching and irritation..