Hirschsprung disease is characterized by the absence of parasympathetic ganglion cells in both submucosal (Meissner) as well as myenteric (Auerbach) plexuses in the distal gastrointestinal tract. The most likely cause is failure of vagal neural crest cells to migrate into the involved segments of the bowel between 5 and 12 weeks of gestation. The denervated colon undergoes persistent contraction causing functional obstruction. It typically presents in term neonates with failure to pass meconium in the 1-2 days after birth. The incidence is 1 in 5000 live births with male predominance. This image is from a suction biopsy of the rectum showing absence of ganglion cells in the submucosal plexus as well as the presence of hypertrophic submucosal nerve fibers.