A 4-day-old girl presents with her parents to the pediatrician for a routine visit. She was feeding well until this morning when she had several episodes of vomiting. The parents describe the vomitus as “bright green” and the patient has shown little interest in feeding since then. She was born at 36 weeks gestation to a 37-year-old G2P2 mother. The pregnancy was complicated by gestational diabetes, and all prenatal testing was unremarkable. The patient has not yet regained her birth weight and is in the 46th percentile for height and the 36th percentile for weight. The patient’s temperature is 99.2°F (37.3°C), blood pressure is 68/46 mmHg, pulse is 132/min, and respirations are 32/min. On physical exam, the patient is in mild distress. She has no dysmorphic features. Her abdomen is distended and firm without guarding. Bowel sounds are hypoactive. The patient’s abdominal radiograph can be seen in Figure A and the patient’s upper gastrointestinal series can be seen in Figure B. Which of the following is the most likely etiology of this patient’s condition?
Hirschsprung disease
Duodenal atresia
Meconium ileus
Intestinal malrotation
Intestinal malrotation
This patient presents with bilious vomiting and an upper gastrointestinal series demonstrating the “corkscrew” appearance of the distal duodenum and proximal jejunum, which is consistent with a diagnosis of intestinal malrotation.

Intestinal malrotation most commonly presents in newborns with bilious emesis. This condition increases the risk of midgut volvulus where the intestines create a closed loop. Abdominal radiographs are rarely diagnostic but are useful in excluding bowel perforation. An upper gastrointestinal series is the diagnostic test of choice and demonstrates an abnormally placed duodenum with a ligament of Treitz on the right side of the abdomen and a “corkscrew” appearance of the distal duodenum and proximal jejunum. Treatment is with surgical derotation of the bowel or exploratory laparotomy if perforation has occurred.

Adams and Stanton review the evidence regarding the diagnosis and treatment of neonatal bowel obstruction. They discuss how malrotation, jejunoileal atresia, duodenal atresia, and colonic atresia are common causes of this finding. They recommend surgical management of these conditions.

Figure/Illustration A is an abdominal radiograph showing a paucity of air in the abdomen (red circle). These findings are consistent with nonspecific findings of intestinal malrotation.

Figure/Illustration B is an upper gastrointestinal series showing a right-sided ligament of Treitz and a “corkscrew” appearance of the distal duodenum (red circle). These are classic findings of intestinal malrotation.

Incorrect Answers:
Answer A: Although duodenal atresia presents with bilious vomiting, the “double bubble” sign would be seen on an abdominal radiograph, which reflects air trapping in both the stomach and the 1st portion of the duodenum. Treatment is with surgical repair of the obstructed segment.

Answer B: Hirschsprung disease may also cause bilious vomiting, but an abdominal radiograph would demonstrate proximal colonic distension with little air in the rectosigmoid colon. Hirschsprung disease is also well visualized on contrast enema, on which a transition point can be seen between the proximal dilated colon and the narrow sigmoid. Treatment is with excision of the defective segment.

Answer D: Jejunal atresia can also lead to bilious vomiting, although a “triple bubble” sign would be seen on an abdominal radiograph with air additionally filling the proximal jejunum. Treatment is with excision of the atretic segment and anastomosis of the bowel lumen.

Answer E: Meconium ileus may present with bilious emesis, but multiple dilated loops of bowel would be seen on an abdominal radiograph. Meconium ileus is better characterized by contrast enema, on which a microcolon can be visualized. Treatment is with the removal of the meconium and treatment of the underlying cystic fibrosis, if present.

Bullet Summary:
Intestinal malrotation presents in newborns with bilious emesis, an upper gastrointestinal series demonstrating a misplaced duodenum, and a “corkscrew” appearance of the distal duodenum and proximal jejunum.