- Hirschsprung’s disease is a rare condition that happens when a baby is born without nerve cells in the lower part of their intestines.
- The condition makes it difficult for babies to pass stool.
- Without treatment, Hirschsprung's Disease can lead to other serious medical conditions, like Hirschsprung's associated enterocolitis (HAEC).
What is Hirschsprung’s disease?
Hirschsprung’s disease (also called Hirschsprung disease or HSCR) is a rare condition in which a baby is born without nerve cells (known as ganglion cells) in the lower part of the intestine. This makes it difficult to pass stool. If left untreated, it can lead to serious complications (medical issues).
Who can be affected by Hirschsprung’s disease?
Hirschsprung’s disease affects about 1 in every 5,000 children. It is more likely to affect males. Children with certain genetic syndromes may also be more likely to have Hirschsprung’s disease. The most common is Down syndrome (Trisomy 21), which affects 10 out of every 100 children with Hirschsprung’s disease.
What are the different types of Hirschsprung’s disease?
- Short-segment Hirschsprung’s disease is the most common type. It is diagnosed in 8 out of 10 children with the disease. In this type, ganglion cells are missing only from the rectum (just inside the anus) and sigmoid colon (the lowest part of the colon, the part of the large intestine just above the rectum). This part of the intestine is called aganglionic because it is missing ganglion cells.
- Long-segment Hirschsprung’s disease is a less common but more severe type in which the aganglionosis affects a longer length of the colon.
- Total Colonic Aganglionosis is when the entire colon is missing ganglion cells. This type occurs in only 5 out of every 100 cases.
- Total Intestinal Aganglionosis is the least common type. It involves the entire small and large intestine. This happens in just 1 out of every 100 children with Hirschsprung’s disease.
What causes Hirschsprung’s disease?
Hirschsprung’s disease is a disease of the enteric nervous system (ENS), the network of nerve cells throughout the gastrointestinal tract (the digestive pathway through your child’s stomach and intestines, also called the digestive tract). The gastrointestinal tract controls how the body absorbs nutrients from food, pushes food and waste along the intestine and passes stool.
Before a child is born, the nerve cells that form the ENS develop from a group of cells called neural crest cells. While a baby develops during pregnancy, neural crest cells travel from the esophagus to the stomach, small intestine and large intestine until they fill the entire length of the digestive tract. Hirschsprung’s disease occurs when the neural crest cells fail to fill the entire digestive tract. This leaves the end of the intestine aganglionic (without ganglion cells).
Usually the aganglionic area is found in the lower end of the digestive tract. Sometimes it can extend farther up the colon and into the small intestine. The absence of nerve cells keeps the digestive tract from working properly. This means your child cannot pass stool normally.
What are symptoms of Hirschsprung’s disease and how do doctors diagnose it?
The most common symptom of Hirschsprung’s disease is when a baby fails to pass meconium stool (a baby’s first stool) within the first 48 hours of life. However, up to half of all newborns who have the disease succeed at passing stool within 48 hours. This means that even though your baby may pass stool within 48 hours, there may still be a chance they have Hirschsprung’s disease.
Nearly 9 out of every 10 cases of Hirschsprung’s disease are diagnosed in newborns or within the first several months of life. Other symptoms in newborns include:
- Abdominal distension (stomach swelling)
- Feeding difficulty
The other 1 out every 10 cases are diagnosed later in childhood. It is less common to be diagnosed in adolescence (teenage years) or adulthood. In these cases, the condition is usually recognized and diagnosed when children or adolescents have severe constipation.
Is Hirschsprung’s disease genetically inherited (passed down through families)?
About 8 out of every 10 cases of Hirschsprung’s disease happen randomly in families with no history of the disease. The other 2 out of 10 cases are hereditary (related to a family history of the condition). Hereditary cases are more often associated with long-segment aganglionosis.
If you or your partner are pregnant and have Hirschsprung’s disease in the family, there is a slightly higher chance that your child may be born with the disease. It is often not possible to predict if it will be passed down to your baby. There are many different genetic mutations (changes in the DNA, or genetic material) that might affect how nerve cells in the colon develop and cause Hirschsprung’s disease.
At least 11 genes are currently known to be associated with Hirschsprung’s disease. The most common is the RET gene. The RET gene controls nerve development in the intestine before birth. A gene mutation may damage the RET gene so the nerves in the colon do not develop properly. Many children with Hirschsprung’s disease have a mutation in the RET gene, but not all.
How do doctors test for Hirschsprung’s disease?
There are many tests doctors can do to check for Hirschsprung’s disease. These tests include:
- Contrast enema is when a catheter (a thin, flexible tube) is placed into your child’s rectum and injected with a safe dye while doctors take an abdominal X-ray (X-ray of the belly area) to confirm whether your child has the disease. On the X-ray, they can check the shape of the lower intestine.
- Rectal biopsy is when a doctor takes a small sample of tissue from the rectum and checks it under a microscope. Doctors typically do a biopsy if the care team sees signs or symptoms of Hirschsprung’s disease on the contrast enema and your child’s medical history and physical exam.
- Anorectal manometry (ARM) is when a doctor inserts a small balloon into your child’s rectum and inflates the balloon. In children without Hirschsprung’s disease, the balloon causes the internal anal sphincter to relax. This is called the recto-anal inhibitory reflex (RAIR). In children with Hirschsprung’s disease, the sphincter does not relax and the RAIR is absent.
How do doctors treat Hirschsprung’s disease?
Treatment for Hirschsprung’s disease starts with medical treatment that leads up to surgery (called pull-through surgery) to remove the aganglionic bowel. Early diagnosis and starting medical treatment as soon as possible are important to keep your child healthy and prevent complications.
Once doctors confirm that your child has Hirschsprung’s disease, they will begin treatment with anal dilations and/or rectal irrigations. These are important ways of decompressing (emptying) the colon and helping your child pass stool. The pediatric surgeon will teach you how to do this at home with your child.
- Anal dilations are performed once or twice a day. This is when an anal dilator is placed into the rectum. Anal dilators are metal or plastic rods placed into the rectum to help widen and/or relax the anus. If the dilations do not successfully empty the colon, your child will start rectal irrigations.
- Rectal irrigation is when a catheter helps to flush the rectum and remove stool with saline (a saltwater solution) once or twice a day.
When will my child have surgery?
Your child’s pediatric surgeon will help you decide when they can perform pull-through surgery. In this surgery, the aganglionic part of your child’s intestine is removed and the healthy section of the intestine (the part with normal nerve cells) is attached to the rectum. Most babies with Hirschsprung’s disease have surgery within the first several months of age.
In children with short-segment HSCR, the surgeon can figure out the best time for pull-through surgery. Children with long-segment HSCR may need an ostomy bag before pull-through surgery. If your child needs an ostomy bag, they will first have surgery to create an ostomy (an opening in the small or large intestine). This means stool can empty into a bag on the outside of the body instead of building up inside the body. Pull-through surgery is done when your child is older, usually at least 10-12 months of age.
What happens after surgery?
After surgery, your child’s care team can help with pain control and monitor for stool output (how much stool your child produces and passes). They can also help with feeding once your child’s digestive tract starts to work again.
The pediatric surgeon may ask you to continue to dilate your child’s anus every day to keep it from scarring. Caring for the skin around the anus is very important. It is common for children to have diarrhea after pull-through surgery. Diarrhea can irritate the skin around the anus. Apply barrier creams immediately after surgery to help prevent severe diaper rash.
What are possible complications of surgery for Hirschsprung’s disease?
Most children do very well after their pull-through surgery. Some may develop problems with how their digestive tract works. This can include obstructive symptoms, fecal incontinence and enterocolitis.
Obstructive symptoms occur when a child has difficulty passing stool. This is the same as having severe constipation. There are 5 possible causes:
- Mechanical obstruction (when the intestine is blocked)
- Internal anal sphincter dysfunction (when the anal sphincter, which is the muscle that helps open and close the anus, does not relax properly to release stool
- Transition zone pull-through (when not enough intestine was removed at the first operation)
- Colonic dysmotility (when the colon does not work properly)
- Functional constipation (when your child tries to avoid passing stool for various reasons)
If your child has signs of obstruction, the care team will do a physical exam (including rectal exam), contrast enema and rectal biopsy. Treatment depends on the cause of the obstruction. It may include anal dilation, surgery, Botox® injection into the anal sphincter to relax the sphincter, laxatives, enemas or behavioral therapy.
Fecal incontinence (accidental stool leakage) can happen in children with Hirschsprung’s disease. Some cases of soiling are due to pseudo-incontinence (overflow of stool if your child is severely constipated). This can be treated with bowel management (laxatives and/or enemas). Soiling can also be caused by an overly active colon or by abnormal anal sphincters or pelvic nerves (nerves in or around the pelvis). Treatment can include medications that slow down the colon, changes to your child’s diet or enemas.
Enterocolitis, also known as Hirschsprung-associated enterocolitis (HAEC), is the most serious complication. Enterocolitis can occur before or after pull-through surgery. Symptoms of enterocolitis include:
- Severe diarrhea
- Abdominal distension
Enterocolitis affects about 6 out every 10 children before pull-through surgery. It also affects about 4 out of every 10 children after pull-through surgery. Children with Down syndrome and long-segment aganglionosis have a higher risk of developing enterocolitis.
Enterocolitis must be treated promptly. If the enterocolitis is mild, treatment includes antibiotics and rectal irrigation. More severe cases require admission to the hospital for rectal irrigations, IV antibiotics and IV fluids.
What is the ongoing research on treating Hirschsprung’s disease?
There are many ongoing areas of research for Hirschsprung’s disease, including:
- New Treatment Options
- Development of stem cell therapy for Hirschsprung’s disease. The idea is that the adult stem cells or a patient’s own cells can be isolated from the intestine and grown in a dish. The cells could then be transplanted into the aganglionic intestine to replace the missing nerves. Several labs around the world are working on this as a possible new therapy for Hirschsprung’s disease with the goal of avoiding the need for surgery and improving long-term health for patients. Scientists are still learning whether the transplanted cells can improve how the intestines work.
- How to Prevent or Treat Enterocolitis
- Understand what causes enterocolitis in the first place. Researchers have found disease-causing bacteria in the intestine of children with Hirschsprung’s disease. Some scientists hope probiotics (healthy bacteria) might lower the risk of enterocolitis by restoring normal, healthy gut bacteria. However, researchers are still looking for evidence that shows a connection between specific groups of bacteria and the development of enterocolitis.
- How other abnormalities in the intestines of children of Hirschsprung’s disease may contribute to the development of enterocolitis. Researchers are actively studying these abnormalities as well.
- Quality of Life of Children with Hirschsprung’s Disease
- Involvement of mental health professionals to improve children’s social and emotional well-being.
- Planning for care transitions as children with Hirschsprung’s disease enter adulthood. Not planning for this important transition to adult medical care can lead to lapses (delays) in care that can negatively impact a child’s quality of life. Smooth transitions of care from childhood into adulthood are essential to ensure that children’s medical needs are properly met by the appropriate care providers.
To learn more about Hirschsprung’s disease, or to learn how you can help support the research being done to cure the disease, contact Allan Goldstein, MD, chief of Pediatric Surgery at MassGeneral Hospital for Children, at email@example.com.