Intestinal malrotation and midgut volvulus

What it is

Intestinal malrotation is caused by an arrest in the normal rotation of the gut during fetal development, leaving the bowel and the mesentery abnormally positioned in the abdominal cavity. Midgut volvulus is the torsion of a malrotated midgut, which produces mechanical bowel obstruction and primarily affects neonates and infants. The rule to carry is short: bilious vomiting is malrotation until proven otherwise, and malrotation must be considered in every infant with bilious emesis. 30% present within the first week of life and 50% within the first month.

How it presents

Malrotation on its own is mostly asymptomatic. Midgut volvulus is the one that shows itself:

• Bilious vomiting with abdominal distension in a neonate or infant
• Signs of bowel ischemia, that is hematochezia
• Lethargy, abdominal distention and bloody stools

When the picture is one of duodenal obstruction, the bilious vomiting comes without abdominal distension. Older children and adults present differently, with recurrent episodes of abdominal pain and vomiting, failure to gain weight, and malabsorption. Abdominal examination is unreliable.