A generation ago, many people suffered from stomach ulcers that caused continued discomfort and, in severe cases, required surgery. Dyspepsia was not just a medical condition but a term used to describe general irritability: behaviour characteristic of people with too much acid in their stomach.

In rich countries medicine has made these problems history. There are two reasons. Modern drugs regulate the level of stomach acidity in most patients. And we know the main cause of stomach ulcers and can therefore cure them inexpensively. Barry Marshall and Robin Warren, two Australian scientists, were awarded this year’s Nobel Prize for medicine for this latter discovery.