Hirschsprung's Disease

Question 1

Hirschsprung’s Disease Definition

Answer 1

aka Congenital Aganglionic Megacolon

Failure of normal innervation of the distal colon by the ganglion cells of the myenteric plexus colon remains contracted and impairs faecal movement

Question 2

Hirschsprung’s Disease Epidemiology

Answer 2

Incidence: M:F = 3:1; 1 in 5,000 live births

Question 3

Hirschsprung’s Disease Clinical Presentation

Answer 3

• Typically only rectosigmoid involvement but may extend to entire colon
  
  • no meconium within first 24 h
  • palpable stool on abdominal exam with empty rectum on digital rectal exam
  • intermittent diarrhea, BM only with rectal stimulation
  • constipation, abdominal distention, vomiting, failure to thrive

Question 4

Hirschsprung’s Disease Complications

Answer 4

• enterocolitis
  * may be fatal, peak incidence 2-3 months of age
  • toxic megacolon and perforation

Question 5

Hirschsprung’s Disease Diagnosis

Answer 5

• abdominal x-ray
  * cannot see gas in rectum
  • barium enema
    
    • proximal dilatation due to functional obstruction, empty rectum
  • manometric studies
    
    • shows failure of anal sphincter relaxation, may have false positives
  • rectal biopsy
    
    • definitive diagnosis (absent ganglion cells)

Question 6

Hirschsprung’s Disease Treatment

Answer 6

• nonsurgical if short segment
  * increase fibre and fluid intake, mineral oil
  • surgical
    
    • colostomy and re-anastomosis