Hirschsprung's disease (also called congenital megacolon, aganglionic megacolon) is a congenital disorder of the large intestine characterized by the absence or marked reduction of parasympathetic ganglion cells in the colorectal wall. This disorder impairs intestinal motility and causes severe, intractable constipation.
Without prompt treatment, an infant with colonic obstruction may die within 24 hours from enterocolitis that leads to severe diarrhea and hypovolemic shock. With prompt treatment, the prognosis is good.
Hirschsprung's disease occurs in 1 in 5,000 to 1 in 2,000 live births. It's up to seven times more common in males than in females (although the aganglionic intestinal segment is usually shorter in males than in females) and is more prevalent in whites. Total aganglionosis of the large intestine affects both sexes equally. Clinical effects usually appear shortly after birth, but mild symptoms may not be recognized until adolescence or early adulthood.
Hirschsprung's Disease develops before a child is born. Normally, nerve cells grow in the baby's intestine soon after the baby begins to grow in the womb. These nerve cells grow down from the top of the intestine all the way to the anus. With Hirschsprung's Disease, the nerve cells stop growing before they reach the end.
No one knows why the nerve cells stop growing. But we do know that it's not the mother's fault. Hirschsprung's Disease isn't caused by anything the mother did while she was pregnant.
Some children with Hirschsprung's Disease have other health problems, such as Down's syndrome and other rare disorders.
Signs and Symptoms
In a neonate with Hirschsprung's disease, the history commonly reveals failure to pass meconium within the first 24 to 48 hours after birth and vomiting of bile-stained or fecal contents. The family history may disclose that siblings, parents, or other relatives have had difficulty passing stools.
On inspection, the infant may have abdominal distention, causing him to breathe rapidly and, possibly, grunt. A stool mass may be felt on palpation. Rectal examination reveals a rectum without stools; then, when the examining finger is withdrawn, an explosive gush of malodorous gas and liquid stools occurs.
In more advanced disease, the patient may have a history of anorexia, nausea, and lethargy. Inspection may show evidence of dehydration, such as pallor, loss of skin turgor, dry mucous membranes, and sunken eyes. In patients with severe disease, failure to grow is characterized by wasted extremities and loss of subcutaneous tissue, with a large protuberant abdomen.
The older infant, child, or adult usually complains of intractable constipation (usually requiring laxatives and enemas). In adolescents and adults, the examination also reveals poor physical condition as well as the symptoms described above.
Adult megacolon, although rare, usually affects men. The patient with this disorder may report a history of chronic, intermittent constipation, with possible rectal bleeding. On inspection, this patient appears in poor physical condition and has a distended abdomen.
Rectal biopsy showing absence of ganglion cells allows a definitive diagnosis. Suction aspiration, using a small tube inserted into the rectum, may be performed initially.
Full-thickness surgical biopsy (under general anesthesia) may be performed if findings from suction aspiration are inconclusive.
Barium enema in older infants, children, and adults shows a narrow segment of distal colon with a sawtooth appearance and a funnel-shaped segment above it to help confirm the diagnosis and identify the extent of intestinal involvement. Significantly, infants with Hirschsprung's disease retain barium longer than the usual 12 to 24 hours, so delayed films are often helpful when other characteristic signs are absent.
Rectal manometry reveals failure of the internal anal sphincter to relax and contract.
Upright plain films of the abdomen show marked colonic distention.
Surgery to restore normal defecation is the treatment of choice. The most effective surgical procedure involves pulling the normal ganglionic segment through to the anus. Before surgery, preliminary bowel preparation with an antibiotic, such as neomycin and nystatin, is necessary.
Corrective surgery in an infant is usually delayed until the child is at least 10 months old. Management of an infant until the time of surgery consists of daily colonic lavage to empty the bowel. If total obstruction is present in the neonate, a temporary colostomy or ileostomy is necessary to decompress the colon.
There are no guidelines for the prevention of Hirschsprung's disease.
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