The bulge between the anus and urethra in infants may be due to boils, anal perineal fistula, abscesses, etc. The causes are different and the treatments are different, so you should consult the doctor in time, and take medication or surgical treatment, etc. as prescribed by the doctor. 1. Boil: It is a purulent inflammation of the deep follicles and surrounding tissues, usually manifested as a raised lump, which can be relieved by topical topical ointment, such as mupirocin ointment, to alleviate the symptoms and reduce pain. 2. anogenital perineal fistula: it is an abnormal fistula between the anal canal and the perineum, vulva or vestibule, usually formed in the late embryonic development, presenting as a bulge, and usually requiring surgical treatment. A small number of children with large fistula does not affect normal life, do not have to operate, need to strengthen the care, keep private parts clean. 3. abscess: usually caused by bacterial infection, infant skin is delicate, low resistance, often contact with feces around the anus, it is easy to form abscesses, the phenomenon of bulging, hard lumps, usually through antibiotic drugs, such as penicillin, etc., to control the development of the disease. Infant medication needs to be used under the guidance of a doctor, not blindly self-medication, so as to avoid adverse effects, pay attention to hygiene in daily life, keep the affected area dry, can be improved.