There are more reasons for fishy odor in the lower body, which may be caused by vaginal inflammation, pelvic inflammatory disease, cervical cancer and so on. 1. Vaginal inflammation: ① Trichomonas vaginitis: may secrete purulent thin and smelly discharge, accompanied by vulvar itching. ② bacterial vaginosis: typical secretions are thin and fishy odor, but also mild vulvar itching and other symptoms. 2. Pelvic inflammatory disease: if there is pelvic inflammatory disease, gynecological examination of the vagina can be seen in purulent smelly secretion, uterine tenderness or adnexal pressure, combined with the history, physical signs and blood tests can help diagnosis. 3. Cervical cancer: there may be vaginal discharge as thin as rice-water with fishy odor, and there may be contact bleeding, such as after sexual life or gynecological examination, which can be clearly diagnosed by cervical cytology and cervical biopsy. Fishy smell of the lower body may also exist for other reasons, need to go to the hospital, under the guidance of professional doctors to identify the causes, and actively deal with.