Breastfeeding mothers whose breasts are infected with bacteria that cause mastitis are usually advised to withhold their milk from their babies because mastitis needs to be treated with antibiotic drugs and the milk may contain bacteria. Mastitis patients are usually treated with antibiotics such as penicillin, and the milk may contain medication, some of which can affect the baby. In severe cases of mastitis, the mother’s milk may contain bacteria or pus, which can cause digestive symptoms such as vomiting and diarrhea in the baby. Mothers with mastitis are advised not to give milk to their babies and go to the hospital for a detailed examination and treatment under the doctor’s guidance. And you can use breast pump to suck out the milk to promote the healing of mastitis.