While much of our digestive tract is alkaline, the stomach is an exception, containing hydrochloric acid which is important for initial digestion and killing of many bacteria. When the stomach and small intestine lining (mucosa) is damaged, this acid may cause injury resulting in a peptic ulcer. The word ‘peptic’ describes the acidic component of the digestive tract, while ‘ulcer’ refers to an eroded area in the mucosa.
Peptic ulcers may be gastric ulcers or duodenal ulcers. If the ulcer occurs in the stomach, it is called a gastric ulcer. If it occurs just after the stomach, in the first part of the small intestine (duodenum), it is called a duodenal ulcer.