A nervous reflex whereby stretching of the wall of the duodenum results in inhibition of gastric motility and reduced rate of emptying of the stomach. It is a feedback mechanism to regulate the rate at which partially digested food (chyme) leaves the stomach and enters the small intestine. Receptors in the duodenal wall detect distension of the duodenum caused by the presence of chyme and also raised acidity (i.e. low pH) of the duodenal contents due to excess gastric acid. They send signals via the parasympathetic nervous system, causing reflex inhibition of stomach-wall muscles responsible for the stomach emptying.