Symptoms are related to the length of affected colon. Patients typically have infrequent, explosive episodes of diarrhea due to functional abdominal obstruction. Symptoms range from chronic progressive constipation to obstruction. About 70% to 90% of newborns with Hirschsprung's disease fail to pass meconium in the first 24 hours of life.27,28 If not diagnosed in the neonatal period, most will present with poor feeding, difficulty having bowel movements, and progressive abdominal distention.28 Those who present with abdominal obstruction or enterocolitis are more likely to present in the first week of life.27 Older children may have episodes of recurrent fecal impaction, failure to thrive, hypoalbuminemia, malnutrition,29 or infrequent, explosive episodes of diarrhea due to functional abdominal obstruction. Hirschsprung's disease must be differentiated from functional constipation in older children. The key physical examination finding is a tight anal sphincter with an empty rectum and upon termination of a rectal exam there is an explosive discharge of stool or flatus.30 Patients may also have abdominal distention and palpable fecal material on abdominal examination. Children with Hirschsprung's enterocolitis initially present with abdominal distention, foul-smelling watery stool, lethargy, and poor feeding. This progresses to fever, dehydration, emesis, and hematochezia. As the disease evolves, intestinal epithelial inflammation progresses to erosion and eventual perforation27 (Fig. 45-3).
Children suspected of having Hirschsprung's disease who are not acutely ill should be referred to a pediatric surgeon or gastroenterologist for assessment, investigation, and management. The key investigations are a contrast enema and a rectal biopsy.
Children with enterocolitis require inpatient management aimed at preventing and limiting disease progression. Those with apparent sepsis or shock require the approach described in the previous section on NEC.
Surgical correction of Hirschsprung's disease provides near-normal gastrointestinal function for most children.31 However, some patients experience some long-term postoperative complications. Persistent constipation or fecal incontinence ranges from 2.5% to 13%.31 This may be a reason for emergency department presentation months after surgery.