Hirschsprung's disease Congenital aganglionic megacolon

• Facts:
  Enlargement of the colon, caused by bowel obstruction resulting from an aganglionic section of bowel (the normal enteric nerves are absent)
  
  Starts at the anus and progresses upwards
  
  Length of bowel that is affected varies but seldom stretches for more than about 30 cm.
  
• History / PE:
  Delayed passage of meconium
  Abdominal distension
  Constipation
  
• Diagnosis:
  Baby who has not passed meconium within 48 hours of delivery
  Definitive diagnosis is made by suction biopsy of the distally narrowed segment
• Treatment:
  Surgical removal (resection) of the abnormal section of the colon, followed by reanastomosis
• Associated With:
  Down's syndrome