Hirschsprung’s Disease

This is a disease where there's a congenital absence of parasympathetic ganglion cells in the myenteric plexus in the distal bowel and rectum. In cases where the entire colon is affected, it's called Total Colonic Aganglionosis. This aganglionic section of the bowel doesn’t relax, therefore stays constricted, causing bowel obstruction.

N.B. The myenteric plexus is needed for gut peristalsis.

The main risk factor for this disease is Family history.

20% of neonates with this disease also have Hirschsprung-Associated Enterocolitis (HAEC), in which the baby presents 2-4 weeks after birth with fever, distension, bloody diarrhoea, and features of sepsis. This can lead to Toxic megacolon, which is life-threatening. Other associated conditions are:

• Downs syndrome

• Neurofibromatosis

• MEN Type 2

N.B. Stasis of stool without passage leads to bacterial overgrowth and then secretory diarrhoea (enterocolitis).

Presentation

• Delay in passing meconium (> 48 hours)

• Abdominal pain and distension

• Vomiting

• Chronic constipation from birth – Poor response to movicol disimpaction regimes

• Poor weight gain

• Failure to thrive

N.B. Typically, patient may have explosive passage of liquid and foul stools, particularly following a rectal examination.

Investigations

• XR

• Rectal biopsy

Management

• Surgical resection of aganglionic bowel section