Propulsion in the digestive system is a process by which food travels through the alimentary canal. The process includes both the act of swallowing and peristalsis. Peristalsis is the movement of food through the digestive system via alternating waves of relaxation and muscle contractions.
Digestion begins with chewing food, called mastication. It then moves to the propulsion phase, during which food is swallowed and moves through the alimentary canal. Peristalsis is the main movement in the propulsion process, where a ring of muscle relaxes and contracts, moving the food bolus down the digestive tract. With the exception of the first segment of the esophagus, all propulsion is enacted by smooth muscles throughout the digestive tract.
Two main groups make up the digestive system organs: the alimentary canal (or gastrointestinal tract) and the accessory organs, which include teeth, tongue, salivary glands and liver. The alimentary canal consists of the mouth, the stomach, and both the small and large intestines.
Dysmotility occurs when the muscles in the digestive tract malfunction. If the contractions are impaired, food becomes trapped within the digestive system, which can lead to nausea, bloating and even malnutrition if nutrients aren't properly absorbed. Dysmotility can be caused by hereditary factors, although medications can also be a cause for certain dysmotility disorders.