Peptic Ulcer Disease
A peptic ulcer occurs when the lining of the digestive tract is eroded by gastric acid and generally occurs when there is an imbalance between gastric injury and mucosal defense.
Gastric acid is produced by parietal cells in the stomach. Parietal cells are stimulated in response to gastrin, acetylcholine and histamine, and inhibited by somatostatin and prostaglandins. Gastric acid plays an important physiological role by helping absorb nutrients and providing an role in immunity. Gastric defenses include the mucous and bicarbonate layer, vascular supply and epithelial barrier function.
H.pylori and NSAIDs account for more than 90% of peptic ulcers, with other less common causes including Crohn’s disease, Zollinger-Ellison syndrome and malignancy.