What is an ulcer?

Ulcers are sores on the lining of your digestive tract. Your digestive tract consists of the esophagus, stomach, duodenum (the first part of the intestines) and intestines. Most ulcers are located in the duodenum. These ulcers are called duodenal ulcers. Ulcers located in the stomach are called gastric ulcers. Ulcers in the esophagus are called esophageal ulcers.