Hirschsprung disease (aganglionic megacolon) occurs when certain nerve cells in the wall of the colon do not form the right way when the fetus is growing.
In a person who does not have Hirschsprung disease, large muscles move gas and stool through the colon with the help of nerve cells called ganglion cells. Children with Hirschsprung disease do not have ganglion cells in the rectum. They sometimes do not have them in other parts of the colon either. Therefore, gas and stool get backed up. This can cause partial or total bowel obstruction. They can have problems passing gas and stool. Almost all children with Hirschsprung disease will need surgery.
The levels of Hirschsprung disease include:
- Ultrashort segment: Missing ganglion cells in the last one to two centimeters of the rectum.
- Short-segment: Missing ganglion cells in the rectum and sigmoid colon (the last segment of the colon).
- Long-segment: Also missing ganglion cells in the first third of the colon.
- Total colonic aganglionosis: Lack ganglion cells throughout the colon. This level is the least common. It causes more severe symptoms than other forms of the disease.
Hirschsprung disease occurs in about 1 out of 5,000 live births. It is three times more common in boys than girls. About 12% of cases are linked to a genetic disorder. This is most often Down syndrome or a rare condition called Mowat-Wilson syndrome.
About 80% of people with the disease do not have a family history of the disease. But, if one parent has Hirschsprung disease, there is about a 1% chance the child will have it too. If a couple has a child with Hirschsprung disease, there is a 4% chance that a sibling will be born with it. It appears that if a parent or child has long-segment Hirschsprung disease, the chances a sibling will be born with Hirschsprung disease are higher than if the parent or child has ultrashort or short-segment Hirschsprung disease.
Hirschsprung Disease Symptoms
Eighty percent of children with Hirschsprung disease show symptoms in the first six weeks of life. In fact, symptoms are most often seen during the first 24-48 hours of life. The most common symptoms in this time frame include:
- Not having a bowel movement
- Bloating of the belly
- Throwing up
But, if only a short segment of a child’s colon lacks ganglion cells, symptoms may not be noticed for many months or even years. These symptoms can appear before or after a child is diagnosed or has surgery to treat the disease:
- Sepsis (an infection that overwhelms the body)
- Constipation that gets worse over time
- Small, watery stool
- Loss of appetite
- Delayed growth
Children with Hirschsprung disease are at increased risk for infections that can cause serious and even life-threatening problems. These infections include enterocolitis (bacterial overgrowth in the colon) and peritonitis (which occurs when a bowel obstruction causes the colon to rupture).
Diagnosing Hirschsprung Disease
A careful physical exam and testing will be done to diagnose Hirschsprung disease. Testing includes:
- Abdominal X-ray: An X-ray of the belly may show a bowel obstruction. This test is a first step. It cannot give an exact diagnosis of Hirschsprung disease.
- Contrast enema: This test uses X-ray images and an enema solution with a contrast solution. The solution makes the features of the colon show up better on an X-ray. This is the most helpful imaging study to assist in finding out if a child has Hirschsprung disease.
- Rectal biopsy: This test gives the definitive diagnosis. It involves taking a sample of the cells in the rectum for a pathologist to view under a microscope. The pathologist confirms that a child has Hirschsprung disease based on the absence of ganglion cells and other abnormal nerve-related findings. In infants, the care team does a “suction” rectal biopsy at the bedside in the hospital room. Since there are no sensory nerves at the site of biopsy, the procedure is not painful. If this is inconclusive or if the patient is older, a surgical biopsy is done under general anesthesia in the operating room.
- Anal manometry: This test measures anal pressure. It also checks if normal reflexes of the rectum and the anus are present. It can be done at the bedside in the hospital room.
Hirschsprung Disease Treatment
Each child with Hirschsprung disease has unique needs. The multidisciplinary care team will make a treatment plan suited for your child’s condition and overall health. Based on your child’s needs and stage of treatment, the care team may include:
- Specialized pediatric colorectal surgeon
- Dedicated nurse
- Pediatric gastroenterologist specializing in motility (motion of the digestive system)
- Registered dietician
- Pelvic floor physical therapist
- Social worker
- Child life specialist
- Other experts as needed
Almost all children with Hirschsprung disease need a surgery called a “pull-through procedure”. This involves taking out the diseased segment of colon. Then the rest of the colon is pulled down and connected to the anus. Sometimes, the surgeon can do this surgery using minimally invasive laparoscopic or robot-assisted surgery. This can mean less pain, less blood loss, smaller scars with faster healing and shorter hospital stays, compared to what patients may have with an “open” or traditional surgery.
Some patients, in particular those with long-segment Hirschsprung disease, may need sodium supplements. A simple urine test is used to check your child’s sodium levels. Your child’s primary care doctor and nutritionist, can prescribe the right oral sodium supplement. Patients who need sodium supplements need to be followed closely for growth and watched closely for dehydration.
Long-Term Outlook for Children with Hirschsprung Disease
Even after surgery, children with Hirschsprung disease may have constipation, fecal incontinence or enterocolitis. This affects their long-term outcomes. But, with a successful surgery and long-term follow-up care, most children are able to achieve normal bowel habits.
Other Treatment Options
Patients can have constipation, fecal incontinence and enterocolitis before and after surgery. A number of other treatment options exist such as bowel management, sacral nerve stimulation, and biofeedback (therapy to help improve the strength and coordination of pelvic floor muscles that are responsible for bowel and bladder control). The collaborative care team will work with you to figure out the best treatment options to help your child overcome any challenges he or she faces and have the best quality of life possible.