Peristalsis is a coordinated, rhythmic contraction and relaxation of muscles in the walls of the gastrointestinal tract and other tubular structures, such as the ureters and fallopian tubes. It propels the contents of these tubes forward, mixing and breaking them down in the process.

In the gastrointestinal tract, peristalsis is controlled by the enteric nervous system, which is a network of nerves and ganglia located within the walls of the digestive tract. These nerves coordinate the contraction and relaxation of the muscles to move food and liquids from the mouth to the anus.

Peristalsis is essential for the proper functioning of the digestive system. It allows for the mixing and breakdown of food, the absorption of nutrients, and the elimination of waste products.