Baby’s red anus may be related to allergy, eczema, infection and so on. 1. Allergy: baby’s diaper or diaper is not soft enough and rough, may cause friction to the baby’s anal skin, causing skin allergies, redness and itchy symptoms. 2. Eczema: baby’s skin is more delicate, in a humid environment may cause eczema, such as not timely change diapers, diapers, cover a longer period of time, may cause the baby’s anus redness symptoms. 3. Infection: baby anal skin with bacterial infection, may also appear anal redness symptoms. Baby red anus may also have other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor’s treatment.