Braaaaains (Update 7/16/2011 dead link).

Once dismissed as a simple collection of relay ganglia, the enteric nervous system is now recognized as a complex, integrative brain in its own right. Although we still are unable to relate complex behaviors such as gut motility and secretion to the activity of individual neurons, work in that area is proceeding briskly—and will lead to rapid advances in the management of functional bowel disease.