Itching is rare.[17] The exact reasons for the disruption of vaginal flora leading to BV are not fully known.[18] However, factors associated with BV include antibiotic use, unprotected sex, douching, and using an intrauterine device (IUD).[19] The role of sex in BV is unknown, and BV is not considered an STI.[14] The diagnosis of BV is made by a health care provider based on the appearance of the discharge, discharge pH > 4.5, presence of clue cells under the microscope, and a characteristic fishy odor when the discharge is placed on a slide and combined with potassium hydroxide ("whiff test").[14][16] The gold standard for diagnosis is a gram stain showing a relative lack of lactobacilli and a polymicrobial array of gram negative rods, gram variable rods, and cocci.