Final answer:
Hirschsprung's disease is a condition characterized by the absence of nerve cells in the rectosigmoid area of the colon, leading to a transition zone between the normal or narrow caliber rectosigmoid segment and the markedly dilated descending colon. It causes symptoms of constipation, abdominal pain, and failure to pass stool. Treatment involves surgical removal of the affected segment of the colon.
Step-by-step explanation:
The classic finding described in the question is associated with Hirschsprung's disease, also known as congenital aganglionic megacolon. It is a condition characterized by the absence of nerve cells in the rectosigmoid area of the colon, leading to a transition zone between the normal or narrow caliber rectosigmoid segment and the markedly dilated descending colon. This results in the accumulation of stool and distention of the colon.
Hirschsprung's disease is caused by a developmental defect in the enteric nervous system, which controls the movement of stool through the intestines. Symptoms typically appear in infancy or early childhood and include constipation, abdominal pain, and failure to pass stool. Treatment involves surgical removal of the affected segment of the colon to allow normal bowel function.