A gastric or peptic ulcer is a sore that can develop on the walls of the stomach. When the protective lining in our stomach stops working it leads to inflammation or stomach ulcer. The digestive system gets eroded by acidic digestive juices and hence a sour stomach may be an early sign of this disease. Recent studies have established the link between a gastric ulcer and stomach cancer. Let's have a look at the various aspects of a stomach ulcer.