Normally water cannot reach the stomach without swallowing, if a gastric tube is used, it can pass through the tube to the stomach without swallowing.
The esophagus and trachea diverge at the epiglottis of the pharynx. The role of the epiglottis is similar to that of a living valve, under the innervation of the laryngeal nerve, the larynx is lifted slightly forward during swallowing, and the epiglottis closes the mouth of the trachea in a downward direction, which prevents foreign bodies from entering the trachea and choking or asphyxiation occurs; during respiration or speech, the epiglottis opens up the laryngeal cavity and closes off the esophagus.
Under normal circumstances, if there is no swallowing action, the esophagus is in an occluded state, and water cannot automatically flow through the esophagus into the stomach. However, if there is a need to use nasal feeding or gastrointestinal decompression, gastric intubation can be performed and water can pass through the gastric tube into the stomach without swallowing.