Can be differentiated by barium enema or water-soluble contrast enema (water soluble preferred as less risk of perforation) Meconium Plug Syndrome: Leads to failure to pass meconium but symptoms should resolve after passage of plug.If not recognised early this can lead to sepsis and death (1). This stasis can lead to bacterial proliferation and the subsequent complication of Hirschsprung’s enterocolitis, which has a mortality rate of 25-30%. Increased intraluminal pressure can lead to decreased blood flow and deterioration in the mucosal layer. It can lead to proximal bowel dilatation which can present as abdominal distension. The accumulation of faeces in the rectosigmoid region is responsible for the functional obstruction, which is the cause of many of the symptoms. Faeces in the rectum fail to trigger relaxation of the internal anal sphincter, due to aganglionosis. The aganglionic segment remains in a tonic state leading to failure in peristalsis and bowel movements. ![]() It is also accepted that sometimes normal cell migration occurs but the neuroblast fails to properly develop due to apoptosis, improper differentiation, or failure in proliferation (4). ![]() The most common accepted aetiology of this disease is due to the arrest of the neuroblast, derived from neural crest cell migration in fetal development between week 8 to 12. The enteric nervous system is derived from the vagal segment of neural crest cells which migrate along the vagus nerve to enter the foregut mesenchyme in a cranial to caudal direction. Hischsprung’s disease is where ganglionic cells of the myenteric and submucosal plexuses in the bowel aren’t present proximally from the anus to a variable length along the large intestine. Even rarer, the distal small bowel is affected, and this is associated with a high mortality and morbidity (1). Rarely, there’s total colonic aganglionosis, where the entire colon is affected, which tends to be the severest form of the disease. The long-segment disease is significantly less common, making up 10% of the cases, where the aganglionosis extends past the rectosigmoid portion of the colon to the splenic flexure. The short segment is the most common, consisting of 85% of cases, where the aganglionosis is restricted to the rectosigmoid portion of the colon (figure 1). There are three main subtypes of Hirschsprung’s disease, which are short-segment, long-segment, and total colonic aganglionosis disease. HD is strongly associated with chromosomal abnormalities, with 10-15% HD cases associated with trisomy 21 (Down Syndrome). The strongest association with Hirschsprung’s, is the Receptor tyrosine kinase (RET) gene, a proto-oncogene on chromosome 10q11. The main genes that are associated with the disease are those that encode the proteins for the RET signaling pathway and endothelin type B receptor pathway. ![]() There are several genes that are believed to be involved. ![]() Males have a higher incidence to female, and the male: female ratio is estimated to be 4:1(3). The most common clinical feature at presentation is abdominal distension and bilious vomiting with failure to pass meconium (2). Around 90% of these present in the neonatal period, with the median age of presentation at 2 days. The international incidence of Hirschprung disease is believed to be 1 case per 1,500-1,700 (1).
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