A duodenal ulcer is a type of peptic ulcer that occurs in the first part of the small intestine called the duodenum. It is a common gastrointestinal disorder that can cause symptoms like abdominal pain, bloating, nausea, vomiting, and loss of appetite. There are several synonyms for the term duodenal ulcer, including peptic ulcer disease, gastric ulcer, stomach ulcer, and digestive ulcer. These synonyms have similar characteristics like increased acid production and damage to the stomach lining. Treatment for a duodenal ulcer should involve reducing the production of stomach acid and promoting the healing of the ulcer with medication and lifestyle changes.