A yellowish foreign body down there mostly refers to abnormal leukorrhea, which may be caused by trichomoniasis, gonorrhea, cervicitis and other diseases. 1. Trichomonas vaginitis: this disease is mainly caused by Trichomonas vaginalis infection, which can be transmitted through sexual contact or indirect contact, and common high-risk factors include multiple sexual partners and long-term application of antibiotics. The vaginal discharge of the patient is thin purulent or foamy, yellowish green, yellowish white or grayish yellow in color, and itchy and painful at the same time. 2. Gonorrhea: This disease is caused by Neisseria gonorrhoeae infection and is mainly spread through sexual contact. Most female patients are asymptomatic or have mild symptoms after infection. Symptoms such as purulent discharge, urinary urgency, painful urination, and increased vaginal discharge, which is mostly yellow, may occur. 3. Cervicitis: The common cause of this disease is pathogen infection, such as Chlamydia trachomatis, herpes simplex virus, etc., and secondly, it is also related to hormonal imbalance, vaginal flora disorders, cervical injury and other reasons. Most patients are asymptomatic, some patients will have symptoms of increased vaginal discharge, which can be yellowish or grayish, purulent, and often accompanied by an odor. There are many reasons for yellow discharge down there, it is recommended to go to the hospital in time to clarify the cause of the disease.