A full-term newborn has not passed meconium within the first 48 hours of life and is exhibiting abdominal distension and vomiting. The healthcare provider suspects Hirschsprung's disease. What is the underlying pathophysiologic cause of this condition?

A. Overstimulation of parasympathetic nerves resulting in rapid bowel transit is incorrect because Hirschsprung’s disease is characterized by decreased or absent bowel motility, not increased motility. Rapid transit would lead to diarrhea rather than constipation and failure to pass meconium. B. Absence of ganglionic nerve cells in a portion of the colon, causing a lack of peristalsis is correct because Hirschsprung’s disease is a congenital disorder caused by aganglionosis. The affected segment of the colon lacks enteric (Meissner and Auerbach) ganglion cells, resulting in failure of peristalsis, functional obstruction, and accumulation of stool proximal to the affected area. C. Obstruction caused by hypertrophy of intestinal smooth muscle is incorrect because this mechanism is more consistent with conditions such as pyloric stenosis, not Hirschsprung’s disease. Hirschsprung’s is a neurologic defect, not a muscle hypertrophy problem. D. Inflammation of the intestinal mucosa leading to motility loss is incorrect because Hirschsprung’s disease is not an inflammatory condition. While inflammation may occur secondary to bowel obstruction, it is not the primary pathophysiologic cause.