What is Hirschsprung disease (HD)?
Hirschsprung disease (HD) is a disease of the large intestine (colon) and results in a blockage of the intestine so that stool cannot pass through. HD usually occurs in children. Some children with HD can't have bowel movements at all, and the stool creates a blockage in the intestine. If HD is not treated, stool can fill up the large intestine, causing serious problems such as infection, bursting of the colon, and even death.
HD occurs in one of every 5,000 births, and more often in boys than in girls. It is sometimes associated with genetic diseases such as Down’s syndrome.
How does Hirschsprung disease (HD) cause constipation?
Normally, muscles in the large intestine push stool to the anus, where stool leaves the body. The intestine’s ability to push and relax is enabled by nerve cells in the intestine called ganglion cells. A person with HD does not have these nerve cells in part of the large intestine, creating the problems associated with the disease. Sometimes these nerve cells are missing from only a few centimeters, but they also can be missing from long segments of the large intestine.
For people with HD, the healthy muscles of the intestine push the stool until it reaches the rigid part of the intestine (the part without the nerve cells). At this point, the stool stops moving. New stool then begins to collect behind it.
Sometimes the ganglion cells are missing throughout the whole large intestine and even parts of the small intestine.
When the diseased section of the intestine reaches or includes the small intestine, it is called long-segment disease. When the diseased section includes only part of the large intestine, it is called short-segment disease.
What causes Hirschsprung disease (HD)?
HD develops before a child is born. Normally, nerve cells grow in the baby's intestine soon after the baby begins to develop in the womb. These nerve cells grow down from the top of the intestine all the way to the anus. With HD, the nerve cells stop growing before they reach the end.
It is unclear why the nerve cells stop growing; however, there is no evidence that it is caused by the mother’s actions or activities while she is pregnant.
What are the symptoms of Hirschsprung disease?
Symptoms of HD usually show up in very young children. Sometimes, however, they don't appear until the teenage years or adult life. The most common symptoms include:
- Failure to pass meconium (contents of the fetal intestine) shortly after birth
- Failure to pass first stool within 24 to 48 hours after birth
- Constipation (possibly worsening over time)
- Abdominal swelling
- Vomiting (usually starts gradually)
- Watery diarrhea (in newborns)
- Poor weight gain
- Slow growth (in children under 5 years)
- Malabsorption (nutrients from food are not absorbed by the small intestine)
- Loss of appetite