All are true about Hirschsprung disease Except

Hirschsprung disease, also known as congenital aganglionic megacolon. Diagnosis of Hirschsprung disease requires documenting the absence of ganglion cells within the affected segment.The distal intestinal segment that lacks both the Meissner submucosal and the Auerbach myenteric plexus ("aganglionosis"). Coordinated peristaltic contractions are absent and functional obstruction occurs resulting in dilation proximal to the affected segment.Hirschsprung disease typically presents with a failure to pass meconium in the immediate postnatal period. Obstruction or constipation follows, often with visible, ineffective peristalsis, and may progress to abdominal distention and bilious vomiting.The rectum is always affected, but the length of the additional involved segments varies widely, from the rectum and sigmoid colon in most cases to the entire colon in severe cases.Ref: Robbins Pathology; 9th edition; Page no: 752