Hirschsprung

Congenital aganglionosis of the distal bowel of unknown etiology. Begins with the anus, which is always involved, and continues proximally for a variable distance. Both the myenteric (Auerbach) and submucosal (Meissner) plexus are absent, resulting in reduced bowel peristalsis and function.

• Transition zone from abnormally small distal to dilated proximal colon
• Normal rectum should always be larger than sigmoid

Clinical Presentation

• Patients do not pass meconium within the first 24 hours of life.
• Abdominal distension with bilious vomiting or nasogastric aspirates.

See Also

• Neonatal small left colon