Differential Diagnosis of Newborn/Neonatal Vomiting

-Benign gastroesophageal reflux ( i.e immature lower esophageal sphincter ) regurgitation of food shortly after feeding .
No further symptoms , healthy children with normal development

-Hypertrophic pyloric stenosis
Regurgitation - projectile nonbilious vomiting electrolyte imbalances ( alkalosis and hypokalemia ) * physical examination may reveal an olive mass on palpation of epigastrium
*typically starts from between 2nd and 7th week of age

-Midgut volvulus /Malrotation /Duodenal atresia * bilious vomiting * abdominal distention * Imaging may reveal signs like the double bubble sign ( duodenal atresia ) etc

Note: The list is not exhaustive as there are many more causes associated with newborn vomiiting

I think that the answer is not pyloric stenosis, which presents with PROJECTILE non-bilious vomiting 4-6wks (classically first born baby boy).

@brise - I think it is the same concept as the pyloric sphincter. In pyloric stenosis, it takes a few weeks for the muscle to actually grow enough to cause an obstruction, so perhaps the same concept applies to the LES muscle- hasn't had time to grow enough to keep stomach contents from regurgitating in a newborn. That would make sense why it would resolve over time. Just a thought.

Just to add to what others have already elaborated upon:

Esophageal spasm - irregular disorganized contractions of esophageal musculature, would cause dysphagia, or immediate regurgitation in this new born. This would probably happen with every feed.

Gut malrotation (Midgut malrotation) - presents with bilious vomiting due to duodenal obstruction via Ladd Bands formation.

Tracheoesophageal atresia - would present with cyanosis, drooling, and excessive coughing. Air would be present in the stomach, and can't pass a nasogastric tube through to the stomach.