peristalsis (pe-ri-stal-sis) n. a wavelike movement that progresses along some of the hollow muscular tubes of the body, such as the intestines. It occurs involuntarily, induced by distension of the walls of the tube. Alternate contraction and relaxation of the circular and longitudinal muscles tends to push the contents of the tube forward.
—peristaltic adj.

peristalsis Series of wave-like movements that propel food through the gut or digestive tract. It is caused by contractions of the smooth involuntary muscle of the gut wall. The reverse process, antiperistalsis, produces vomiting.

peristalsis Waves of involuntary muscular contraction and relaxation that pass along the alimentary canal, forcing food contents along. It is brought about by contraction of the circular muscles of the gut wall in sequence.

peristalsis The rhythmic alternating contraction and relaxation of smooth muscle that forces food through the intestinal tract in peristaltic waves.

peristalsis The rhythmic waves of muscular contraction by which matter is passed along the alimentary canal.