Spitting up differs from vomiting in that it is an effortless return of liquid rather than the result of muscle contractions. Because the throat and nose are connected, the formula or milk sometimes comes out of the nose rather than, or in addition to, the mouth. Almost all infants spit up, mainly because they cannot sit upright during feeding, but the phenomenon also can be a sign of a medical condition that requires treatment, so you should consult your pediatrician for a wellness check.
Often, spitting up through the nose is harmless. The valve between the esophagus and the stomach is immature in infants, and sometimes is is not able to keep all of the stomach's contents in place. If you feed your baby too much at a time, or if your infant eats too fast or swallows air, it can exacerbate the spitting up. Your pediatrician can give you advice about how much and how often to feed your baby to minimize the symptom. Spitting up usually ceases on its own sometime between the ages of 7 and 12 months.
Sometimes spitting is related to gastro-esophageal reflux. If the spitting up causes your baby discomfort or if he is not gaining weight at a normal rate, he may require medical intervention. If you see a green color---caused by bile---or evidence of blood in the material he spits up, or if the spitting up causes coughing or choking, he needs medical attention. If the spitting up does not stop by early childhood, let your pediatrician know.
A rare condition called pyloric stenosis can cause the sphincter muscle at the bottom of a baby's stomach to become abnormally tight and may prohibit liquid from passing out of the stomach into the intestines. This condition is persistent and the spitting up becomes progressively worse. It requires medical intervention, but it can be treated effectively. If your baby's spitting up is intermittent, it likely is not the result of pyloric stenosis, but if the phenomenon is persistent, bring it to your pediatrician's attention.
The material that your baby spits up may irritate her nose, but this does not pose a serious medical concern. If she spits up a large amount of liquid, there is a possibility that she is not retaining sufficient nourishment to support her growth. You should monitor her growth and weight gain as well as developmental milestones. Your pediatrician can help you determine if she is developing on schedule or if intervention is needed.
To reduce the likelihood of your baby spitting up, feed him before he gets very hungry and try to keep him in an upright position during and after feeding. Holding works best because an infant's position in a car seat actually can make the condition worse. Burp him every three to five minutes during feeding. If you use a bottle, check the nipple to ensure it only lets out a few drops at a time under pressure or when you turn it upside down. This will help ensure your baby doesn't eat too fast. Smaller, more frequent feedings also can help reduce spitting up episodes.