Solution: Hirschsprung's disease is characterized by an absence of ganglion cells in Auerbach's and Meissner's plexus in the affected bowel. The involved segment is of variable lengths, but always begins distally and progresses to some point proximally, usually in the sigmoid colon. The majority of affected patients are male and they usually present in the neonatal period. Abdominal distention, vomiting and delayed passage of meconium are common presenting symptoms. The definitive diagnosis is biopsy, but radiographic findings can be helpful. The rectosigmoid ratio is < 1 in these patients and the transition can be abrupt or gradual depending on the age of the patient. The treatment is surgical resection of the affected segment.