Final answer:
The process termed peristalsis, is the wave of muscular contractions that moves a food bolus through the GI tract, from the stomach to the anus. It is distinct from other processes like segmentation, mastication, and churning, as it is responsible for propulsion along the entirety of the alimentary canal.
Step-by-step explanation:
The wave of muscular contractions within the GI tract that moves a food bolus away from the stomach and toward the anus is called peristalsis. This process involves alternating waves of muscle contraction and relaxation that propel the food through the digestive tract. It is a part of mechanical digestion, which, unlike chemical digestion, does not alter the chemical nature of food but instead breaks it into smaller pieces, thus increasing its surface area and mobility.
Peristalsis occurs throughout the gastrointestinal tract as the muscular walls of the alimentary canal squeeze sequentially, creating narrowing or shortening to push the food along in one direction. In the small intestine, a similar process called segmentation aids in mixing food with digestive juices, but it is characterized by localized contractions that move food content back and forth within small sections of the intestine. Other processes in mechanical digestion include mastication (chewing) and the churning of food in the stomach, which further breaks down the food into an acidic mixture called chime. However, peristalsis is the specific process responsible for moving the food bolus towards the anus after it exits the stomach.