A 54-year-old man underwent gastroscopy

(endoscopy of the upper digestive tract) for non-specific digestive disorders.

The oesophagus and stomach appear macroscopically fine, but changes are only

visible in the duodenum, where several samples are therefore taken for

histological examination. The final diagnosis is peptic duodenitis,

inflammation of the duodenum, which is a precursor to the development of the

ulcer. This inflammation is usually caused by the