What are the other Names for this Condition? (Also known as/Synonyms)

• Aganglionic Megacolon
• Congenital Megacolon
• HSCR (Hirschsprung Disease)

What is Hirschsprung Disease? (Definition/Background Information)

• Hirschsprung Disease is an intestinal disease, where the ganglion cells of the nerves of the intestine are absent at birth. Without these nerve ganglion cells, the intestine cannot contract to move material through it, leading to severe constipation
• The nerve ganglions may be absent from all or part of the intestine. However, this condition most commonly affects, only the last part of the large intestine (colon)

The two most common types of Hirschsprung Disease are known as “short-segment” and “long-segment” disease.

• 80% of individuals with Hirschsprung Disease have short-segment disease, affecting only the last part of the large intestine
• In long-segment disease, the nerve ganglion cells are missing from most of the large intestine; hence, the symptoms are more severe
• In very rare cases, the nerve ganglion cells may be missing from the entire large intestine and sometimes, from parts of the small intestine, as well. This condition is called as a total colonic aganglionosis
• Even more infrequently, the nerve ganglion cells may be absent from the entire small and large intestine, a condition known as total intestinal aganglionosis

Who gets Hirschsprung Disease? (Age and Sex Distribution)

• Hirschsprung Disease is a congenital condition that is approximately present in 1 in 5000 births
• Short-segment disease is about 4-times more common in males, than females
• Long-segment disease is equally common, both in males and females

What are the Risk Factors for Hirschsprung Disease? (Predisposing Factors)

The risk factors of Hirschsprung Disease include:

• In most cases (80% of the time), there is no prior family history of the disorder. The other 20% of the cases do run in families, with multiple members of the same family being affected
• Hirschsprung Disease is linked to other congenital genetic disorders, including Down syndrome
• It is also associated with congenital heart defects and multiple endocrine neoplasia type II

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Hirschsprung Disease? (Etiology)

• Hirschsprung Disease is caused by nerve ganglion cells failing to grow in the intestine, during development of the embryo, prior to birth
• The disease is believed to have genetic causes, but these genetic causes are not yet completely understood
• Certain genes are important for the development of these nerves in the intestine, and these include the RET, EDNRB, and EDN3 genes. Mutations of these genes are known to cause some cases of Hirschsprung Disease
• In families, where multiple family members are affected, it is usually inherited in an autosomal dominant pattern. This means that only one parent with the ‘disease gene’ is required, in order to pass on the disease to their children. However, for some unknown reasons, not every child who inherits the defective gene, actually develops Hirschsprung Disease; some children develop normally, without the condition affecting them

What are the Signs and Symptoms of Hirschsprung Disease?

• The most common symptom associated with Hirschsprung Disease is severe constipation. This may sometimes lead to a complete obstruction of the intestines
• Other signs and symptoms include:
  • Abdominal pain, swelling or bloating
  • Vomiting and diarrhea
  • Malnutrition
  • Slowed growth and poor feeding

How is Hirschsprung Disease Diagnosed?

A diagnosis of Hirschsprung Disease would involve:

• Physical exam with evaluation of family medical history
• Radiographic studies (of abdomen)
• Rectal biopsy: The biopsy is examined under the microscope by a pathologist, to arrive at a definitive diagnosis. The rectal biopsy will show an absence of ganglion nerve cells
• Barium enema of intestine
• Anal manometry to measure the rectal pressure

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Hirschsprung Disease?

Complications due to Hirschsprung Disease include:

• Severe abdominal inflammation with frequent (smelly) diarrhea, which may take place before any treatment measures are advocated
• Intestinal rupture
• Short bowel syndrome
• Development of enterocolitis, after a surgical rectification of the condition

How is Hirschsprung Disease Treated?

The treatment measures for Hirschsprung Disease include:

• To reduce pressure in the bowel, serial rectal irrigation procedure is employed
• Surgical removal of the defective part of the colon (called colectomy), and reattachment of the functional part of the colon with the rectum. The surgery is performed in a single step or in multiple steps
• To help and regulate the intestinal function, a high-fiber diet with increased fluid intake is recommended
• In order to avoid constipation, prescribed laxatives may be used

How can Hirschsprung Disease be Prevented?

• Hirschsprung Disease is related to genetic and other non-genetic causes, as yet unascertained; the condition cannot be prevented
• Genetic testing of the expecting parents (and related family members) and prenatal diagnosis (molecular testing of the fetus during pregnancy) may help in understanding the risks better during pregnancy
• If there is a family history of the condition, then genetic counseling will help assess risks, before planning for a child
• Regular medical screening at periodic intervals with tests, scans, and physical examinations, are mandatory

What is the Prognosis of Hirschsprung Disease? (Outcomes/Resolutions)

• Children treated early, or those with milder bowel complications have the best prognosis
• Use of surgical techniques to correct the intestinal defect has generally positive outcomes
• Post-operative symptomatic treatment may be required, but these are usually manageable
• Severe abdominal complications can lead to death
• Overall, the prognosis for Hirschsprung Disease is good with early diagnosis and treatment

Additional and Relevant Useful Information for Hirschsprung Disease:

After corrective surgery, there is a 20% probability of the child suffering from enterocolitis, which is a severe inflammatory condition of the digestive tract, caused by a bacterial, viral, or other parasitic infection.