Helicobacter pylori infection and the use of nonsteroidal anti-inflammatory drugs (NSAIDs) including aspirin are the most important causes of peptic ulcer disease. Cigarette smoking also increases the risk, but—although often alleged—there is little evidence to implicate psychological stress. Zollinger–Ellison syndrome, which consists of a gastrin-secreting islet cell tumour (gastrinoma) leading to marked hypergastrinemia, is a rare cause of recurrent peptic ulceration....