Most cases of rotten egg smell in urine are caused by abnormal vaginal discharge, most commonly due to bacterial vaginosis. Bacterial vaginosis is mainly caused by Gardnerella infection, which causes local inflammation of the vagina and results in vaginal discharge that smells like fish and rotten eggs. It is manifested by thin and abundant leucorrhea. Laboratory tests are performed to find out if there is Gardnerella infection, and if there is a (+) result, metronidazole is administered continuously for one week to achieve treatment. After laboratory tests, there is no bacterial vaginosis, to exclude the possibility of cervical cancer or endometrial cancer.