Table of Contents
Overview – Hirschsprung’s Disease
Hirschsprung’s disease, also known as congenital aganglionic megacolon, is a developmental disorder where a section of the colon lacks the enteric ganglion cells necessary for peristalsis. This results in a functional large bowel obstruction, most commonly presenting in neonates with delayed passage of meconium and abdominal distension. Early recognition is crucial to prevent complications like enterocolitis and bowel perforation.
Definition
A congenital condition that causes functional large bowel obstruction due to an absence of ganglion cells (aganglionosis) in the distal colon, resulting in an atonic and obstructed bowel segment.
Aetiology
- Congenital disorder
- Linked to defective neural crest cell migration during embryogenesis
Pathogenesis
- Absence of ganglion cells in the distal colon → loss of peristalsis
- Atonic segment becomes narrowed
- Functional obstruction leads to dilation of proximal bowel
Morphology
- Commonly affects a segment <30 cm in the descending or sigmoid colon
- Narrowed aganglionic segment distally
- Proximal segment is dilated (megacolon)
Clinical Features
Neonatal Presentation (Severe cases)
- Symptoms typically within 48–72 hours of birth:
- Failure to pass meconium within 48 hours
- Abdominal distension
- Bilious vomiting
Infant Presentation (Milder cases)
- Later onset in infancy
- Chronic abdominal distension
- Alternating constipation and diarrhoea
Investigations
- Barium enema: shows transition zone between narrow and dilated bowel
- Anorectal manometry: reveals lack of internal sphincter relaxation
- Rectal biopsy: confirms diagnosis by showing absence of ganglion cells
Management
- Surgical resection of aganglionic bowel
- Pull-through procedure to connect normal ganglionic bowel to the anus
Complications
- Enterocolitis – life-threatening; may occur pre- or post-op
- Bowel perforation
- Death if untreated
Summary – Hirschsprung’s Disease
Hirschsprung’s disease is a congenital cause of functional large bowel obstruction due to aganglionosis, most commonly presenting in neonates. Diagnosis is confirmed via barium enema and rectal biopsy, with surgical resection offering definitive treatment. Prompt management is essential to avoid life-threatening complications such as enterocolitis. For broader context, see our Gastrointestinal Overview page.