[24] Hirschsprung's Disease Flashcards
What is Hirschsprung’s disease?
A congenital condition that affects the large intestine that causes problems with stool
What causes Hirschsprung’s disease?
Missing nerve cells in the muscles of the colon
What cells are absent and where from in Hirschsprung’s disease?
Missing ganglion cells in the myenteric and submucosal plexuses of parts of the large bowel
What effect does the absence ganglion cells have on the segment of large bowel?
Causes it to narrow and contract
What causes the absence of ganglion cells in the segment of large bowel?
Failure of the ganglion cells to migrate into the hindgut during development
What effect does Hirschsprung’s disease have on normal bowel function?
Causes an absence of co-ordinated bowel peristalsis and functional obstruction at the junction between normal and aganglionic bowel
What is the extent of abnormal bowel in Hirschsprung’s?
From the rectum for a variable distance proximal
What does the length of abnormal bowel end in?
A normally innervated dilated section of colon
In what percentage of cases is the constriction confined to the rectosigmoid?
75%
In what percentage of Hirschsprung’s disease is the entire colon involved?
10%
What is the main cause of Hirschsprung’s disease?
Genetics
What percentage of Hirschsprung’s disease cases are linked to a specific genetic mutation?
~50%
What percentage of Hirschsprung’s disease occurs within families with a history?
20%
Does Hirschsprung’s disease occur in isolation?
It can but also with other disorders such as Down’s syndrome
What is the main risk factor for Hirschsprung’s disease?
Family history
When does Hirschsprung’s disease normally present?
In the first few days of life
What is the normal presentation of Hirschsprung’s disease?
Low intestinal obstruction
What symptoms can Hirschsprung’s disease present with?
- Failure to pass meconium in 24 hrs
- Abdominal distension
- Bile-stained vomiting
What is meconium?
The first stool passed by a baby after birth
What is a rarer early presentation of Hirschsprung’s disease?
Severe, life threatening Hirschsprung enterocolitis in the first few weeks
How can Hirschsprung’s disease present in later childhood?
- Chronic constipation
- Abdominal distension
What occurs on rectal examination of a patient with delayed presentation of Hirschsprung’s disease?
Release of a gush of liquid stool and flatus
What investigations can be used to help diagnose Hirschsprung’s disease?
- AXR
- Rectal biopsy
- Anorectal manometry or barium studies
What will an AXR show in Hirschsprung’s disease?
Distal intestinal distension
