- Malrotation can be totally asymptomatic ormay be manifested as chronic, vague abdominal pain, with or without intermittent bilious emesis, and failure to thrive. - The acute onset of bilious vomiting in a neonate is a sign of malrotation until proved otherwise. It demands immediate radiologic evaluation. Upper Gastrointestinal Contrast Study Malrotation is diagnosed by an abnormal position of the ligament of Treitz. The normal location is typically to the left of the veebral column and posterior to the stomach .