Allied disorders of Hirschsprung's disease (ADHD) have been proposed to be the concept
of the functional obstruction of the intestine with the presence of ganglion cells
in the terminal rectum. They are classified into two categories based on pathology:
(1) abnormal ganglia, including immaturity of ganglia, hypoganglionosis (HG), and
intestinal neuronal dysplasia; (2) normal ganglia, including megacystis microcolon
intestinal hypoperistalsis syndrome (MMIHS), segmental dilatation (SD), internal anal
sphincter achalasia (IASA), and chronic idiopathic intestinal pseudo-obstruction (CIIP).
Some of these show poor prognosis, therefore, the establishment of criteria and appropriate
treatment strategies is required.