Peptic ulcer is a non-malignant ulcer of the stomach (called gastric ulcer) or duodenum (called duodenal ulcer). By far most instances are now known to be due to Helicobacter pylori, a spiral-shaped bacterium that lives in the acid environment of the stomach. These ulcers can also be caused or worsened by drugs such as Aspirin and other NSAIDs.

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Endoscopic image of gastric ulcer, biopsy proven to be gastric cancer. ...
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