Nonrotation of the midgut presenting in the adolescent and adult.

The most common abnormality of midgut rotation and fixation is nonrotation of the midgut. This most commonly presents in the neonatal period with duodenal obstruction or midgut volvulus. However, this condition can present outside the neonatal period as chronic abdominal pain, or as an abdominal emergency. Two such cases are reported. Normal and abnormal embryology is described, and diagnosis and management are discussed.