Aims Bilious vomiting in the newborn is a potentially life threatening emergency. Malrotation, a disorder of abnormal intestinal rotation and fixation, predisposes newborns to midgut volvulus. Plain abdominal films and upper gastrointestinal contrast studies form the mainstay of radiological diagnosis.

1. 1) To determine the incidence of surgical pathology in newborns with bilious vomiting referred to a regional paediatric surgical centre.

2. 2) To assess the predictive value of radiological investigations

Methods A total of one hundred and fourteen infants referred for radiological assessment on the day of presentation were identified from the regional radiological database (October 2006–April 2008). Exclusion criteria included abdominal wall defects, congenital cardiac conditions, congenital anomalies and vomiting beyond the neonatal period. A total of 23 infants were excluded. All infants had plain abdominal films and upper gastrointestinal contrast studies. In addition, five infants had abdominal ultrasonography.

Results 18.6% (17/91) of newborns presented with intestinal pathology, of which all 17 required surgery. Thirteen newborns (14.2%) had malrotation (seven had additional midgut volvulus), two had a duodenal web, one each had colonic pneumatosis and intussusception. Plain films and clinical examination did not suggest malrotation in the positive cases. Upper gastrointestinal contrast studies diagnosed malrotation in eleven cases, equivocal diagnosis of malrotation in two cases with midline duodenojejunal junction and a diagnosis of duodenal web in a further two cases. The predictive value of upper gastrointestinal contrast studies in diagnosing malrotation was 85%. Ultrasonography secured the diagnosis of midgut volvulus based on the “whirlpool sign”, in the two equivocal cases with midline duodenojejunal junction and this was confirmed during surgery. All thirteen cases had a Ladd's procedure. None had ischaemic bowel.

Conclusion The incidence of malrotation in our population is less than previously reported, probably because our regional policy dictates that all infants with a single bilious vomit require specialist investigation. This study confirms that clinical examination and plain abdominal films have no predictive value in diagnosing midgut volvulus. The study also confirmed that upper gastrointestinal contrast studies, in combination with ultrasound improves the predictive value in diagnosing surgical pathology.