The enteric nervous system (ENS) is the largest branch of the peripheral nervous system, comprising complex networks of neurons and glia, which are present throughout the gastrointestinal (GI) tract. Although development of a fully functional ENS is required for GI motility, little is known about the ontogeny of ENS function in humans. We studied the development of neuronal subtypes and the emergence of evoked electrical activity within the developing human ENS.