Hirschsprung’s disease was first diagnosed 125 years ago. It is a condition in which nerve cells, or ganglion cells, are absent from the lower part of the colon. Infants born without these ganglion cells are unable to pass stool, which leads to severe abdominal distension, vomiting and the risk of serious intestinal inflammation, referred to as enterocolitis.
Hirschsprung’s disease affects 1 in 5,000 newborns, accounting for over 850 new cases each year in the U.S. and over 26,000 cases worldwide. In 2006, Hirschsprung’s disease led to an estimated 4,275 hospital admissions in the U.S. and 45,000 hospital days.
Despite its prevalence and severity, surprisingly little information is available to families affected by this disease. Equally surprising is the lack of knowledge among healthcare providers.
What Is Hirschsprung’s Disease?
Hirschsprung’s disease occurs when nerve cells (also called ganglion cells) are absent from the lower part of the colon. The segment without nerve cells is called the aganglionic segment and it always starts at the bottom of the colon affecting the lower end. It can also extend up the colon, even into the small intestine. The absence of ganglion cells leaves a portion of the colon essentially paralyzed and unable to propel waste products along its length. This is the reason why babies born with Hirschsprung’s disease are often unable to pass their first “meconium” stool and children diagnosed later in life have severe constipation. In addition to having difficulty passing stool, infants and children with Hirschsprung’s disease also typically have abdominal distension and sometimes develop vomiting and loss of appetite.
What Causes Hirschsprung’s Disease?
Hirschsprung’s disease is caused by the failure of nerve cells to reach the bottom end of the colon. These nerve cells develop very early on in the embryo. These cells migrate through esophagus making a long journey along the intestinal tract to get to the stomach, small intestine and finally the colon. Many genes are required to make this migratory journey possible and if any of these genes function abnormally, then the nerve cells are unable to complete their journey, leaving the lower part of the colon aganglionic and unable to function normally.
How Is Hirschsprung’s Disease Diagnosed?
When concern for Hirschsprung’s disease is raised, your doctor will often order a contrast enema. This is a radiological study where a catheter is inserted into the rectum, contrast is injected and x-rays of the abdomen are taken. Aganglionosis causes a narrowing of the colon, while the normal colon above it will be dilated. This contrast enema is used only to support the possibility that the child has Hirschsprung’s disease. The definitive diagnosis is made by taking a biopsy from the rectum. Usually this procedure, which is painless, is performed without anesthesia. A pathologist examines the biopsy searching for nerve cells. If no nerve cells are found, then the diagnosis of Hirschsprung’s disease is made.