In hirschsprung disease aganglionic segment is?

ANSWER: (B) Normal or contractedREF: Sabiston Textbook of Surgery, 18th ed chapter 71Hirschsprung's disease occurs in 1 out of every 5000 live births and is characterized pathologically by absent ganglion cells in the myenteric (Auerbach's) and submucosal (Meissners) plexus. This neurogenic abnormality is associated with muscular spasm of the distal colon and internal anal sphincter resulting in a functional obstruction. Hence, the abnormal bowel is the contracted, distal segment, whereas the normal bowel is the proximal, dilated portion. The area between the dilated and contracted segments is referred to as the transition zone.