Which is a common disease involving the sores on the esophagus, stomach, and/or small intestine?

A peptic ulcer is an open sore that can form in the lining of the stomach or the first part of the small intestine, and sometimes in the esophagus. GERD involves stomach acid flowing back into the esophagus, gingivitis affects the gums, and gastritis is inflammation of the stomach lining rather than an ulcer.

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