What to smear on the baby’s buttocks rotten, need to be determined according to the specific cause, this symptom or with diaper dermatitis, eczema, rubbing rash and other diseases, can be coated with ellagic acid ointment, zinc oxide ointment, mupirocin ointment, pimecrolimus ointment, hydrocortisone ointment and so on. 1. Diaper dermatitis: baby’s bottom for a long time by the wet impregnation and friction will trigger this disease, the need to clean the buttocks before using the drug, and then apply zinc oxide cream (occasionally allergic) to reduce inflammation and promote epidermal regeneration. In the presence of bacterial infection, mupirocin ointment (occasionally itchy skin) should also be used. 2. Eczema: babies with eczema on the buttocks, if not carefully cared for, may also cause localized skin ulcers, under the premise of good localized skin care, can be applied hydrocortisone ointment (occasional allergies), pimecrolimus cream (occasional skin burning) and other ointments to relieve the condition. 3. Between the rubbing rash: this disease often occurs in the buttock folds, can first use water to rinse clean the baby buttocks on the dirt, and then apply tannic acid ointment (can not be used for a long time on a large area) to improve the condition, usually to help the baby to wash the buttocks, and keep it dry and ventilated. Caused by the baby butt rot there are a variety of reasons, specific medication, need to be used under the guidance of a professional doctor.