enterokinesia
peristalsis
[per″ĭ-stal´sis]When food is swallowed, it passes into the esophagus. Muscular contractions in the wall of the esophagus work the food downward, pushing it into the stomach. Here peristaltic contractions not only move the food in small amounts into the intestine but also aid in the disintegration of the food and help mix it with gastric juice. Peristalsis forces the food into and through the intestine for further digestion until the food waste finally reaches the rectum, from which it is periodically discharged from the body. The waves of peristalsis are irregular; they are stronger at some times than at others. They are also weaker in some people, notably the elderly.
Although the normal peristaltic wave is downward, it is sometimes reversed. Reverse peristaltic action may be triggered by mild digestive upsets or more serious disorders, such as an obstruction in the stomach or intestines.