Six-Week-Old Is Spitting Up

When the word "projectile" is used to describe the quality of spitting or vomiting, pyloric stenosis comes to mind first. The muscle at the end of the stomach is thicker than usual with pyloric stenosis, which may cause a blockage resulting in "projectile" (forceful shooting across the room) vomiting. It is usually diagnosed within the first eight weeks or so of life and happens more often in males. The treatment is an operation that loosens this muscle, so food can more easily pass through, allowing the infant to grow.

It sounds like you are thinking more of "gastroesophageal reflux" where an infant spits up some of the stomach contents after feedings. This is very common to some degree or another in many infants during their first year of life. As you suggest, it happens because the muscle area at the bottom of the swallowing tube (where it meets the top of the stomach) does not close as tightly early on. This area does tighten up on its own within 12 - 18 months. There is not any medicine, exercise, or other treatment that is routinely recommended to make it tighten up earlier.

Simple ideas like frequent burping, placing the baby in a semi-upright position during and after feedings, and making sure feedings are made calmly without bouncing may help minimize the spitting. Remember that what comes out of the mouth with gastroesophageal reflux is seemingly effortless and should be differentiated from other causes for spitting up or vomiting in a young infant. Regardless of the cause for spitting, it is always important to watch for dehydration and to monitor how well the baby is growing.