Congenital megacolon
Overview
Hirschsprung's disease is a blockage of the large intestine due to improper muscle movement in the bowel. It is a congenital condition, which means it is present from birth.
Symptoms
* Constipation * Failure to pass meconium shortly after birth * Failure to pass a first stool within 24 - 48 hours after birth * Malabsorption * Poor weight gain * Slow growth (child 0-5 years) * Swollen belly * Vomiting * Watery diarrhea (in the newborn)
Causes
Muscle contractions in the gut help digested materials move through the intestine. This is called peristalsis. Nerves in between the muscle layers trigger the contractions. In Hirschsprung's disease, the nerves are missing from a short or long part of the bowel. Areas without such nerves can not push material through. This causes a blockage. Intestinal contents build up behind the blockage, causing the bowel and abdomen to become swollen. If the condition is severe, the newborn may fail to pass meconium or stool, and the newborn may vomit. Milder cases may not be diagnosed until a later age. In older children, the disease may be cause chronic constipation, abdominal swelling, and decreased growth. Hirschsprung's disease causes about 25% of all newborn intestinal obstruction. It occurs five times more frequently in males than in females. Hirschsprung's disease is sometimes associated with other inherited or congenital conditions such as Down syndrome.
Diagnosis
During a physical examination, the doctor may be able to feel loops of bowel in the swollen belly. A rectal examination may reveal a loss of muscle tone in the rectal muscles. Tests used to help diagnose Hirschsprung's disease may include: * Abdominal x-ray * Anal manometry (a balloon is inflated in the rectum to measure pressure in the area) * Barium enema * Rectal biopsy
Prognosis
Symptoms improve or are eliminated in most children after surgical treatment. A better outcome is associated with early treatment and shorter bowel segment involvement.
Treatment
The abnormal section of colon must be surgically removed. Sometimes this can be done in one operation. However, it is frequently done in two parts with a colostomy being performed first, and another procedure being performed later in the first year of life.