Hirschsprung Disease in Children

Definition | Aetiology | Pathophysiology | Risk Factors | Signs and Symptoms | Investigations | Management | References

Definition

Hirschsprung Disease is a congenital condition where nerve cells (ganglion cells) are absent from a portion of the colon, leading to a blockage due to the lack of peristalsis in the affected bowel segment. This results in chronic constipation, abdominal distension, and can lead to serious complications such as enterocolitis. Hirschsprung disease typically presents in newborns and infants but can also manifest later in childhood.

Aetiology

Hirschsprung disease is caused by the failure of neural crest cells to migrate completely during fetal development. The absence of these ganglion cells leads to an inability of the affected bowel segment to relax, causing functional obstruction. Most cases are sporadic, but there is also a genetic component in some cases:

• Mutations in the RET gene have been implicated in familial cases.
• Other chromosomal abnormalities, such as trisomy 21 (Down syndrome), are associated with a higher incidence of Hirschsprung disease.

Pathophysiology

In Hirschsprung disease, the absence of ganglion cells in the myenteric and submucosal plexus leads to a lack of peristalsis in the affected segment of the colon. This creates a functional obstruction, with a buildup of stool proximal to the aganglionic segment. The bowel above the obstruction becomes dilated, while the aganglionic segment remains narrow. The result is chronic constipation, difficulty passing stool, and eventual bowel distension.

Risk Factors

• Family history of Hirschsprung disease.
• Male gender (it is more common in boys than girls).
• Associated genetic conditions such as Down syndrome.
• Other congenital abnormalities such as heart defects.

Signs and Symptoms

Hirschsprung disease can present in newborns, infants, and young children, with varying degrees of severity:

• Failure to pass meconium within 48 hours after birth (neonatal period).
• Chronic constipation or difficulty passing stool.
• Abdominal distension.
• Poor feeding and failure to thrive.
• Vomiting (sometimes bilious).
• In severe cases, enterocolitis with fever, explosive diarrhoea, and lethargy may occur.

Investigations

Diagnostic tests are important to confirm Hirschsprung disease and assess the extent of the aganglionic segment:

• Abdominal X-ray: May show dilated bowel loops and air-fluid levels indicative of bowel obstruction.
• Barium enema: Used to visualise the bowel and typically shows a transition zone between the dilated, normal colon and the narrow, aganglionic segment.
• Rectal biopsy: The definitive diagnosis is made by identifying the absence of ganglion cells in the biopsy. This is often performed via a suction biopsy in infants.
• Anorectal manometry: May be used in older children to assess the function of the anal sphincter and confirm the absence of the rectoanal inhibitory reflex.

Management

The primary treatment for Hirschsprung disease is surgical. The goal is to remove the aganglionic segment of the bowel and restore normal bowel function:

Surgical Treatment:

• Pull-through procedure: This is the standard surgery where the diseased segment of the bowel is removed, and the healthy part is connected to the anus. This can be performed either through open surgery or laparoscopically.
• Colostomy: In some cases, particularly if the child is very ill or has enterocolitis, a temporary colostomy may be created before performing the pull-through surgery at a later date.

Postoperative Care and Follow-up:

• Monitor for complications such as enterocolitis, anastomotic leaks, or bowel obstruction.
• Some children may experience long-term issues such as constipation or faecal incontinence, which will require ongoing management with dietary changes, laxatives, or bowel training.
• Follow-up with a paediatric surgeon and gastroenterologist is essential.

References

1. NICE (2024). Hirschsprung Disease: Diagnosis and Management. Available at: NICE Guidance
2. BMJ (2023). Hirschsprung Disease in Children. Available at: BMJ
3. NHS (2023). Hirschsprung's Disease in Infants. Available at: NHS