Babies suddenly not eating breastmilk may be caused by oral ulcers, abnormal breastmilk flavor, too little breastmilk production and other factors. 1. Mouth ulcers: Mouth ulcers may be induced if the baby’s oral mucosa is inadvertently burned or stung. The baby may be irritated during breastfeeding and develop pain, so he or she is reluctant to breastfeed. 2. Breastmilk taste abnormal: If the mother ate some chili, raw garlic and other spicy and stimulating food, it may lead to the secretion of the milk taste abnormal, thus causing the baby does not want to eat breastmilk phenomenon. 3. Breastmilk secretion is too little: if the mother’s milk secretion is too little, the baby is more difficult to breastfeed, even if the sucking time is long, but not get enough milk, so the baby is not willing to eat breastmilk. It is recommended that breastfeeding mothers avoid spicy and stimulating foods, and can drink more chicken soup and fish soup to replenish nutrients. If the baby suddenly does not eat breastmilk, it is recommended to consult a professional doctor. If it is caused by mouth ulcers, you should actively cooperate with the treatment.