What is Hirschsprung’s disease?
Hirschsprung’s disease is a congenital (present at birth) disease that affects around 1 in every 5000 babies. It is usually detected within days of being born but can take up to a year or two after birth to be noticed. The disease is characterized by the inability to pass stool properly through your intestines. When stool passes through your intestines, it is through a process of wave-like squeezing and relaxing that pushes it along. In Hirschsprung’s disease, the nerve cells that control this process are absent. Therefore, stool can simply become stuck in the intestines as nothing is pushing it along. This can lead to a build-up of stool (constipation) and increases the risk of infection in the intestines (enterocolitis).
There are three types of Hirschsprung’s disease (HD), namely short-segment, long-segment, and total colonic, depending on the length of the intestines affected. Short-segment HD, which makes up 80% of patients, involves the rectum and sigmoid colon. These areas connect the anus to the large intestines. In long-segment HD, which makes up 12% of patients, the majority of the large intestines are affected. Total colonic HD, which makes up 7% of patients, involves all of the colon and possibly the small intestines. In a very small percentage of cases, both the entire length of the large and small intestines can be affected, known as total intestinal aganglionosis.
Hirschsprung’s disease can lead to complications that are serious and the disease itself can be problematic for an individual. This article will explore Hirschsprung’s disease and how it affects an individual in quality of life as well as life expectancy.
Signs and symptoms
Hirschsprung’s Disease can be detected early in childhood, usually a few days after birth. As our digestive system is active for our survival and babies are often breastfed immediately after birth, defects in the intestines are highly noticeable. In addition, worried mothers would be keenly observant if their baby seems unhealthy in any way. However, there are some key signs and symptoms listed below:
Failing to pass the meconium
- The meconium is a dark, tar-like stool that babies pass soon after birth.
- Patients with Hirschsprung’s disease can be unable to pass the meconium due to defects in their intestines. However, some Hirschsprung’s disease patients might pass their meconium, so it is not a definitive symptom.
- Patients can present with a swollen belly due to the build-up of stool in their intestines.
- This green fluid is bile and is a bit indicator of illness in a patient.
- Patients will be unable to pass stool even with the help of laxatives.
For worried mothers, these symptoms will be immediately noticeable and patients will often be diagnosed soon after birth. However, it can take some time before these signs and symptoms are noticed in a patient. In older infants and children, other symptoms are not feeding well or not gaining weight. But what causes Hirschsprung’s disease?
Causes and risk factors
Currently, the exact cause of Hirschsprung’s disease is unknown. It is unlikely to be caused due to the mother’s actions during pregnancy. Instead, it has been linked to genetic causes. A number of genes have been identified to cause Hirschsprung’s disease.1 However, in most patients, no obvious genetic mutation has occurred to cause the disease. Therefore, the possibility of Hirschsprung’s disease in a patient is unpredictable to a certain extent and there are no current preventative measures.
Hirschsprung’s disease can also be caused due to an overall greater genetic condition. This includes Down’s syndrome, Mowat-Wilson syndrome, Waardenburg syndrome, and a variety of other genetic conditions. This will be discussed in greater detail below.
Regardless of the cause, the end-point is still the same. The nerve cells associated with the large intestines fail to develop properly, leading to a defect in the bowel. This can lead to possible complications for a patient.
Possible complications
The most likely complication for a patient with Hirschsprung's disease is enterocolitis. Hirschsprung-associated enterocolitis is an inflammation of the large intestines due to infection. This is a serious condition that can be life-threatening and can occur before or after surgery. There are several symptoms of this complication including swelling of the abdomen, fever, diarrhea, rectal bleeding, and lack of energy. If a patient has this complication, they should be rushed to a hospital immediately. They can be treated with antibiotics.2,3
Other complications include:
- An unexpected bowel movement
- Can be very distressing and embarrassing
- Severe constipation or swelling of the intestine
- Can be extremely uncomfortable or painful
- A patient is unable to effectively digest food
- Cannot get the needed vitamins, minerals, and other nutrients for healthy development
- A hole is made in the wall of the intestines
- More common in newborns than in older children
Before we are certain that Hirschsprung’s disease is the condition responsible for these complications, we must diagnose the disease.
Diagnosis
Diagnosis can occur through physical examination, assessment of patient and family history, and identification of key symptoms. Hirschsprung’s disease is usually suspected after the infant fails to pass the meconium. A variety of diagnostic tests can then be used to confirm the presence of Hirschsprung’s disease. These tests include a suction biopsy of the rectum, abdominal X-ray, barium enema, and anorectal manometry.
A biopsy involves taking a section of tissue and assessing it under a microscope for abnormalities. Here, a small section of tissue is taken from the rectum with the help of a vacuum. This tissue is then assessed with a type of staining that highlights nerve cells. In Hirschsprung’s disease, the nerve cells are absent and the staining will not highlight anything. This is a safe method with an extremely low chance of any complications and is currently the “gold standard” of diagnosis.4
An abdominal X-ray can be used to assess the state of the intestines without an invasive procedure. This will show if there is any blockage in the intestines. In addition, a barium enema can be used in an X-ray. This is a contrast agent that can be used to highlight the intestines, allowing a greater assessment of their health and function.5 Finally, an anorectal manometry is a procedure that uses balloons and pressure sensors to assess the health and function of the intestines.6
If these tools reveal other abnormalities, there is a high chance that Hirschsprung's disease is the result of another genetic defect or syndrome. These will be discussed in the next section.
Other associated chromosomal abnormalities
Chromosomal abnormalities are associated with roughly 12% of cases of Hirschsprung’s disease. The most well-known chromosome abnormality which is associated with Hirschsprung’s disease is Down’s syndrome.1,7 This is a syndrome caused by an extra 21st chromosome and causes a plethora of phenotypes in an individual. How Down’s syndrome causes a defect in the intestines is unknown, but the effect is so persistent that any Down’s syndrome child with constipation can be assumed to have Hirschsprung’s.
Mowat-Wilson syndrome is another syndrome that is associated with Hirschsprung’s disease. This is caused by mutations in a gene called ZEB2 on chromosome 2. This syndrome is characterized by an intellectual disability as well as distinctive facial features. Hirschsprung’s disease is present in 50% of patients with this syndrome.
In addition, Waardenburg syndrome is associated with Hirschsprung’s disease. This condition is associated with mutations in a gene called SOX10, which is highly associated with our development. Deafness is also associated with this syndrome.1,7
The presence of Hirschsprung’s disease in these syndromes provides evidence that a genetic component is involved. There is a myriad of mutations that can occur in genes that produce Hirschsprung’s disease as opposed to one key gene. However, a majority of Hirschsprung’s disease patients do not have chromosome abnormalities which obscure the exact cause of the disease from our current knowledge.1,7
Treatments
Currently, the only treatment for Hirschsprung’s disease is surgery which bypasses the defective areas of the intestines. This surgery involves removing the defective areas of the intestines and connecting the remaining healthy sections which is known as a “pull-through” procedure.6 This can be performed in one stage or multi-stages, depending on what the doctor will decide is best for the patient. In addition, it can also be accomplished by open or key-hole surgery depending on which is most appropriate.8
In a multi-stage pull-through procedure, the healthy section of the intestine is first redirected to the surface of the abdomen to an opening known as a stoma. This allows the stool to be removed from the system into a special bag. This is the preferred way if the baby is born prematurely or is critically ill. At a later stage, the full pull-through procedure is performed.8
Outlook
Patients with Hirschsprung’s disease who complete the pull-through surgery generally have a good outlook. The surgery returns bowel movements to normal. However, in some cases, the pull-through surgery may need to be performed again if the first surgery fails. The long-term outlook for redo patients is similarly as effective as a primary procedure.9
Quality of life
Once a successful surgery has taken place, and bowel movements return to normal, patients will enjoy a good quality of life. However, these patients will still have a higher risk of incontinence, constipation, and bladder dysfunction. In addition, they will have a lower gastrointestinal quality of life compared to healthy individuals.9
Mortality rate
Hirschsprung’s disease today has a low mortality rate due to the advances in pull-through surgery. It is reported in the literature that the mortality rate from pull-through surgery can range from 1.25% to 7.1%. Without surgery, this rate will be much higher as a child would be unable to properly digest food.9
Life expectancy
Hirschsprung’s disease is not a terminal illness and is operable with a pull-through procedure. Consequently, there is no great effect on life expectancy in an individual. However, we cannot say this definitively, as there are no studies investigating this factor in Hirschsprung’s disease patients.
Summary
Hirschsprung’s disease is a congenital disorder that affects the intestines. Portions of the large intestines that connect to the rectum cannot pass stool, which leads to a build-up. This can be life-threatening and runs the risk of infection known as enterocolitis. It is likely caused by genetics and is associated with several chromosome abnormalities. However, it is easily treatable with a pull-through operation that removes the affected areas of the intestines. After a successful surgery, there is some diminishment to quality of life, but individuals can enjoy a normal life expectancy.
References
- Passarge E, Bruder E. Genetic bases of Hirschsprung's disease. Pathologe. 2007;28(2):113-8.
- Frykman PK, Short SS. Hirschsprung-associated enterocolitis: prevention and therapy. Seminars in Pediatric Surgery. 2012;21(4):328-35.
- Gosain A, Frykman PK, Cowles RA, Horton J, Levitt M, Rothstein DH, et al. Guidelines for the diagnosis and management of Hirschsprung-associated enterocolitis. Pediatric Surgery International. 2017;33(5):517-21.
- Friedmacher F, Puri P. Rectal suction biopsy for the diagnosis of Hirschsprung's disease: a systematic review of diagnostic accuracy and complications. Pediatric Surgery International. 2015;31(9):821-30.
- Singh CD, Baruah RR. Role Of Barium Enema In The Diagnosis Of Hirschsprung Disease. Journal of Evolution of Medical and Dental Sciences-Jemds. 2016;5(72):5245-8.
- Tang YF, Chen JG, An HJ, Jin P, Yang L, Dai ZF, et al. High-resolution anorectal manometry in newborns: normative values and diagnostic utility in Hirschsprung disease. Neurogastroenterology and Motility. 2014;26(11):1565-72.
- Moore SW. Chromosomal and related Mendelian Syndromes associated with Hirschsprung's disease. Pediatric Surgery International. 2012;28(11):1045-58.
- De la Torre-Mondragon L, Ortega-Salgado JA. Transanal endorectal pull-through for Hirschsprung's disease. Journal of Pediatric Surgery. 1998;33(8):1283-6.
- Menezes M, Puri P. Long-term clinical outcome in patients with Hirschsprung's disease and associated Down's syndrome. Journal of Pediatric Surgery. 2005;40(5):810-2.
