If your baby suddenly spits up milk in a jet-like manner, you should first pick up your baby face down to avoid choking and suffocation caused by the vomit, and you can also complement it with a pat on the back, holding your five fingers together into an empty fist and gently patting it on the back to help your baby expel the vomit. Next, after the vomiting stops, go to the nearest hospital for a relevant examination. There are many reasons why babies appear in this situation, which may be physiological reasons and may be caused by diseases: a. Physiological reasons: 1. Too much milk in the stomach: If the baby eats too much milk at one time, or the interval between two feedings is too short, resulting in too much milk hoarding in the stomach, while the baby’s stomach is relatively flat and small capacity, the pyloric sphincter function is not perfect, it may suddenly occur the performance of large mouth jet-like vomiting, so it is recommended Parents should pay more attention to the amount of milk and feeding time when breastfeeding; 2. Vigorous activities after feeding: If the baby has frequent and vigorous activities after breastfeeding, it may cause the milk in the stomach to repeatedly crash and stimulate the stomach wall, which will eventually cause the baby to suddenly spit up the milk in a big mouth-like situation. It is recommended that parents pay attention to the baby’s activities after feeding, can be moderately soothing, to avoid vigorous movement of the baby; 3, supplemental food added too early: if the baby’s diet is added too early in the stage of not adding supplemental food, may affect the peristaltic function of the gastrointestinal tract, causing the baby to suddenly spit up large mouth-like occurrence of milk, you can consult a doctor at this time the correct time to add supplemental food. Second, the pathological reasons: 1, indigestion: if the baby can not effectively absorb and digest the milk into the stomach, it is easy to trigger the baby sudden big mouth jet-like vomiting, you can take probiotics, lactulose and other drugs under the guidance of the doctor to promote intestinal peristalsis; 2, digestive tract malformations: such as congenital hypertrophic pyloric stenosis, the baby can have a sudden big mouth jet-like vomiting performance, but also often appear urine volume reduction, jaundice and other Symptoms require early surgical treatment; 3, other diseases: gastrointestinal flu, pyloric obstruction, tuberculous meningitis, cranio-cerebral tumors and many other diseases can also lead to the sudden occurrence of large mouth-like vomiting symptoms, the cause and symptomatic treatment.