A newborn vomits after each feeding and starts to develop abdominal distension

nasogastric decompression

This is an example of bowel obstruction with marked distension, multiple air-fluid levels, and poor gas distribution. The obstruction can be partial or complete, and it can due to extrinsic or intrinsic causes. Intrinsic causes include abnormalities of the intestinal system such as atresia or stenosis. Extrinsic causes include compression by veins or malrotation.

Symptoms of obstruction in a newborn include vomiting, abdominal distension, and minimal or no stooling.  Initial treatment involves nasogastric decompression to relieve pain and vomiting. If the infant appears ill, antibiotics are started with the possibility of surgical intervention depending on the severity and cause of the obstruction.

Reference:

Kliegman RM, et al, eds. Nelson Textbook of Pediatrics. 20th ed., 2016.