If there are yellowish things on the underwear: First, it may be that the girl has vulvovaginitis or vaginitis, which is caused by bacterial infection due to lack of local hygiene, resulting in increased vaginal secretions. Secondly, it could be that girls are growing faster or eating foods that contain more hormones, which may lead to an increase in the level of hormones secreted by the ovaries and an increase in vaginal secretions. Therefore, when a girl has yellowish underwear, she should wash it with warm water and observe it for a while if it can be relieved. Also, do not eat foods with high hormone levels, such as farmed fish, shrimp, chicken, and vegetables and fruits that are out of season. If the girl is accompanied by severe itching of the vulva, she needs to go to the hospital to get anti-inflammatory drugs for treatment.