Hirschsprung's disease (constipation)

Question 1

Define Hirschsprung’s disease

Answer 1

Congenital condition characterised by partial or complete colonic functional obstruction associated with absence of ganglion cells 

Question 2

What is the aetiology of Hirschsprung’s disease

Answer 2

Absence of ganglion cells from the myenteric and submucosal plexuses (Meissner’s and Auerbach’s) of the large bowel (parasympathetic)
This results in a narrow and contracted segment of the large bowel 
The region of the normal bowel will extend from the rectum for a variable distance proximally 
The region of abnormal bowel will end up with a normally innervated, dilated colon 
In 75% of cases, the lesion is confined to the rectosigmoid 
In 10% of cases, the entire colon is affected 

Question 3

What are the symptoms of Hirschsprung’s disease

Answer 3

Neonatal intestinal obstruction:
- failure to pass meconium within the first 24h
- abdominal distension
- Bile stained vomiting
- Rectal examination: narrowed segment, withdrawing of the examining finger releases liquid stools and flatus
- Hirschsprung’s enterocolitis (first few weeks of life)

Childhood chronic constipation
- Profound constipation
- Abdominal distension, usually without soiling
- Growth failure

Question 4

What investigations should be done for Hirschsprung’s disease

Answer 4

AXR: Multiple dilated loops of bowel
Suction full thickness rectal biopsy (diagnostic): absence of ganglion cells and presence of large acetylcholinesterase-positive nerve trunks

+/- GI contrast enema: dilated distal segment and narrowed proximal segment
- avoided in those suspected to have Hirschsprung’s who are systemically unwell (?perforation)

Question 5

What is the management for Hirschsprung’s disease

Answer 5

1. Bowel irrigation (help prevent enterocolitis)
2. Surgery: Anorectal pull through
   - Colostomy -> anastomosing normally innervated bowel to the anus
   - Definitive surgical treatment done either trans-anally or with laparoscopic assistance 
   - Total colonic agangliosis: initial ileostomy with later corrective surgery 

Question 6

What are the complications of Hirschsprung’s disease

Answer 6

Ischaemic enterocolitis 
Post-operative enterocolitis, constipation or diarrhoea 
Duhamel-related rectal pouch 
Faecal incontinence- surgically-related or pseudo 
Meconium plug syndrome  
Hirschsprung’s enterocolitis (perf colon)  

Question 7

What is the prognosis for Hirschsprung’s disease

Answer 7

Rectosigmoid disease outcome is good
Soiling is usually treatable

Question 8

What are the risk factors for Hirschsprung’s disease

Answer 8

Down’s syndrome
M>F
Caucasian

Question 9

Describe Hirschsprung’s enterocolitis

Answer 9

Marked by proximal colonic dilatation secondary to obstruction
Thinning of the colonic wall, bacterial overgrowth and translocation of gut bacteria
S/S: fever, abdominal distension, blood diarrhoea
Shock and death follows rapidly
Tx: fluid resuscitation, decompression with NG and rectal tubes, broad spectrum Abx -> surgery (definitive)