The bowel (colon) is a long tube that runs from the stomach to the anus. It is made up of the large and small intestines as well as the rectum. The small intestine is responsible for absorbing the nutrients from food that a person consumes. The large intestine, on the other hand, is responsible for absorbing water from wastes and creating stool. It also pushes the stool into the rectum.
Hirschsprung disease is a congenital disorder. It occurs when nerve cells that are commonly found in the smooth muscles of the colon are missing. These cells control the muscle contractions needed to move food through the bowels. If they are missing, the stool either moves too slowly or stays in the large intestine. This causes the stool to accumulate in the bowel. This increases the risk of bacterial infection in the digestive tract.
The disease can affect any person of any age. However, it is most common in newborns.
Newborns who do not pass stool within 48 hours after birth are suspected of this disease. It is important that they are tested and treated quickly to prevent life-threatening complications.
The disease affects one in every 5,000 newborns. It is more common in boys than girls.
The disease occurs when nerve cells that are supposed to develop in the wall of the intestine do not form during foetal development. These cells are needed to move food forward from the intestines to the rectum. Without them, the stool backs up and causes either partial or complete bowel obstruction.
What prevents the nerve cells from growing while the baby is in the womb is unknown. However, scientists believe that genetic defects increase one’s risk of the disease.
Patients often have other medical problems and syndromes. The most common are Down syndrome and congenital heart defects.
The main symptom of the disease is the inability to pass stool. This does not resolve even when patients are given medicine for constipation. It often occurs shortly after birth. In others, however, the condition develops when they are older. Other symptoms are green or brown vomit and fever as well as a swollen abdomen. In toddlers and older children, symptoms include slow growth and slow weight gain. They cannot also pass stools without the use of suppositories and enaemas.
The disease is diagnosed based on the results of the physical exam and medical tests. During the physical exam, the doctor will check the patient’s abdomen for swelling. He or she will also look for signs of poor nutrition. A rectal exam is also performed. In this test, the doctor will check:
If the rectal canal has narrowed.
If there is a build up of stool.
If rectal muscles have lost their muscle tone.
A rectal biopsy is also used. It is done by taking tissue samples from the large intestine. The samples are then sent to a lab where they are checked for nerve cells. A Hirschsprung disease diagnosis is confirmed if there are no nerve cells in the samples. This test is painless and safe for babies.
Imaging tests that doctors use are abdominal x-ray and lower GI series. An abdominal x-ray can confirm obstructions in the intestines. Lower GI series, on the other hand, are used to confirm if the colon or the rectum has narrowed. Both tests are safe and painless. They are done without the use of pain medications.
Anorectal manometry, on the other hand, is used to measure the function of the rectum. For this procedure, a small balloon is inserted into the child’s rectum. Once inside, the balloon is inflated and deflated a number of times. Rectal muscles that do not relax during the procedure are a sign of Hirschsprung disease.
Treatment of the disease is surgery. The procedure is done to remove the part of the bowel that does not have nerve cells. The part of the bowel that remained is then attached to the anus. The procedure can be done using traditional open surgery or through laparoscopy. The former is done by making one huge incision in the abdominal area. The latter, on the other hand, is a less invasive method. It uses several small cuts where a scope and tiny surgical tools are inserted to make necessary repairs. It shortens hospital stays. It also reduces the common risks of surgery. These include infections and scarring.
In some cases, ostomy surgery becomes necessary. This is advised if some areas of the intestines are inflamed and need time to heal. For this procedure, the surgeon will bring a part of the intestine through an opening in the abdominal wall (stoma). The procedure is called ileostomy surgery if the small intestine is connected to the stoma. On the other hand, it is called a colostomy if the large intestine is the one connected to the stoma.
The general outlook for patients who have undergone surgery is excellent. After surgery, most are able to pass stool normally. Many also do not have lasting complications. However, some children continue to have problems. These include diarrhoea and constipation. They may also leak stool, and their anus may become narrowed again. Their toilet training may also be delayed or become challenging. This is because they need to learn how to coordinate the muscles used in order to pass stool.
Tjaden NEB, et al. The developmental etiology and pathogenesis of Hirschsprung disease. Translational Research. 2013;162:1.
The National Institute of Diabetes and Digestive and Kidney Diseases: Hirschsprung Disease