Peristalsis is simply a series of contraction and relaxation of muscles in a specific manner that helps in the movement of food through the digestive tract. It comprises of the relaxation of smooth muscles, then their contraction behind the already chewed bolus preventing it from moving backward and then further longitudinal contraction to push it forward.

In the Alimentary canal, "Plexus of Auerbach" of Serosa - starts peristalsis.

While, "Plexus of Meissner" - stops peristalsis.