The digestant is generally a main component of digestive fluid, such as dilute hydrochloric acid, amylase, pepsin, trypsin and the like. And the digestant is used for curing the weak secretion function of the digestive tract, and acts as a replacement therapy to quickly restore the normal digestion activities. Some herbs, such as yeast, drug song, hawthorn, malt, Gallus gallus domesticus, also contribute to the digestion. There are some digestants which working by promoting the secretion of digestive juices, such as carnitine (vitamin BT), which can promote the secretion of digestive juices, and enhance the activity of digestive enzymes. In recent years, the drugs enhancing gastrointestinal motility also help the digestive function, such as domperidone (domperidone), metoclopramide, etc., which have been valued and used in clinical practice.