For nasogastric intubation, a small, flexible plastic tube is passed through the nose or mouth into the stomach (nasogastric tube) or duodenum in the small intestine (nasoduodenal tube). Intubation typically causes gagging and nausea, so a numbing agent may be sprayed in the nose and back of the throat.
This procedure can be used for various purposes, such as
Removing a sample of stomach or intestinal contents
Continuously removing the contents of the stomach