A nurse is caring for an infant who has inadequate motility of part of the intestine resulting in a mechanical obstruction. The nurse should identify this finding as a manifestation of which of the following disorders?

A. Pyloric stenosis causes projectile vomiting and dehydration due to gastric outlet obstruction, not inadequate motility of the intestine. B. Hirschsprung's disease (congenital aganglionic megacolon) leads to inadequate motility of part of the intestine and results in a mechanical obstruction. C. Encopresis refers to the involuntary defecation in children, typically related to constipation, not motility issues. D. Enterocolitis is inflammation of the intestine and can cause symptoms such as diarrhea, but it is not characterized by inadequate motility of the intestine.