Value of ultrasound in differentiating causes of persistent vomiting in infants.

A prospective study of abdominal ultrasound was undertaken in 100 consecutive infants who presented with a history of persistent vomiting aged 5 to 90 days. Each infant had a 'test feed' followed by an ultrasonographic scan of the pylorus at the cotside. On test feeding a palpable tumour was evident in 38 infants. On real time ultrasound using the criteria for diagnosing pyloric stenosis, these 38 infants as well as six others were documented as having pyloric stenosis. In the other 56 patients the vomiting settled in six and a barium examination was performed on the remaining 50. This confirmed gastro-oesophageal reflux in 46, two of whom had an associated hiatus hernia, one with a duodenal malrotation, and three were reported as normal. Ultrasound of the abdomen is an accurate, reliable, and rapid screening method to differentiate the causes of severe vomiting in infancy.