Background: We have recently identified hexamethonium-resistant peristalsis in the guinea-pig colon. We showed that following acute blockade of nicotinic receptors, peristalsis recovers leading to normal propagation velocities of fecal pellets along the colon. This raises the fundamental question as to what mechanisms underlie hexamethonium-resistant peristalsis. Aims: In this study we investigated whether blockade of the major receptors that underlie excitatory neuro-muscular transmission are required for hexamethonium-resistant peristalsis to occur. Methods: Video imaging of colonic wall movements was used to make spatio-temporal maps and determine the velocity of peristalsis. Propagation of artificial fecal pellets in the guinea-pig distal colon was studied in hexamethonium, atropine, -conotoxin (GVIA), ibodutant (MEN15596) and tetrodotoxin (TTX). Results: Hexamethonium and ibodutant alone did not retard peristalsis. In contrast, -conotoxin abolished peristalsis in a proportion of preparations, and reduced the velocity of propagation in all remaining specimens. In fact, peristalsis could still occur, in a proportion of animals, in the combined presence of hexamethonium, atropine, ibodutant and -conotoxin. Peristalsis never occurred in the presence of tetrodotoxin. Discussion: The major finding of the current study is the unexpected observation that peristalsis can still occur after blockade of the major excitatory neuro-neuronal and neuro-muscular transmitters. Also, the colon retained an intrinsic polarity in the presence of these antagonists and was only able to expel pellets in an aboral direction. The nature of the mechanism(s)/ neurotransmitter(s) that generate peristalsis and facilitates natural fecal pellet propulsion, after blockade of major excitatory neurotransmitters, at the neuro-neuronal and neuro-muscular junction remains to be identified.