A nurse is caring for an infant who has inadequate motility of a portion 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 involves narrowing of the pylorus, causing vomiting and dehydration, not mechanical obstruction due to motility issues. B. Hirschsprung's disease is a condition where part of the intestine lacks proper motility due to missing nerve cells, leading to a mechanical obstruction and constipation. C. Enterocolitis typically involves inflammation and infection of the intestines, not a motility issue. D. Intussusception is a condition where one part of the intestine telescopes into another, causing an obstruction, but it is not related to motility.