Peptic ulcers are sores that develop in the lining of the stomach, lower esophagus, or small intestine. They’re usually formed as a result of inflammation caused by the bacteria H. pylori, as well as from erosion from stomach acids. Peptic ulcers are a fairly common health problem. There are three types of peptic ulcers: gastric ulcers: ulcers that develop inside the stomach esophageal ulcers: ulcers that develop inside the esophagus duodenal ulcers: ulcers that develop in the upper section of the small intestines, called the duodenum