The gastric folds (or gastric rugae) are coiled sections of tissue that exist in the mucosal and submucosal layers of the stomach. They provide elasticity by allowing the stomach to expand when a bolus enters it. These folds stretch outward through the action of mechanoreceptors, which respond to the increase in pressure. This allows the stomach to expand, therefore increasing the volume of the stomach without increasing pressure. They also provide the stomach with an increased surface area for nutrient absorption during digestion. Gastric folds may be seen during esophagogastroduodenoscopy or in radiological studies.

The gastric folds consist of two layers:

Thickening of the gastric folds may be observed by endoscopy or radiography and may aid in the differential diagnosis of many disease processes including: