The first chronic complaint found to have an unexpected bacterial cause was stomach ulceration.

ECONOMIST: Bugged by disease | The

However, NSAIDs can irritate the stomach lining, and cause ulceration which can lead to bleeding and infections.

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Up to four per cent of patients taking NSAIDs develop serious gastrointestinal complications, including peptic ulceration and bleeding from the stomach and small intestine.

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The system could, for example, be used to explore the binding between Helicobacter proteins and those in the stomach cells that it attacks, in order to find targets for new drugs to block ulceration.

ECONOMIST: Genomics

When I read in the New England Journal of Medicine that a procedure I was to undergo had a 10% risk of "esophageal injury with ulceration, " I forced myself to pay more attention to this statistic than to the tale of a friend who had the same procedure and did well.

CNN: Talk back to your doctor