ABSTRACT
Your colleague asks for advice about a 1-month-old term baby boy who has presented with distention and failure to thrive. He is otherwise well, and having excluded an anorectal malformation, washouts were initially successful. A rectal biopsy was obtained and the results have caused a fair amount of discussion; although no ganglion cells were seen, the size of the nerve fibers was described as “normal,” all less than 40 μm. Since the baby was doing well, the diagnosis of Hirschsprung disease seemed unclear.
