Hospital admission and mortality statistics suggested that peptic ulcer reached a peak prevalence in the mid-1950s. During the Second World War, against this background of serious and common pathology, an epidemic of dyspepsia afflicted both service personnel and civilians alike. In the absence of reliable diagnostic techniques, physicians struggled to distinguish between life-threatening illness and mild, temporary disorders. This article explores the context in which non-ulcer stomach conditions flourished. At a time when fear was considered defeatist and overt psychological disorder attracted stigma, both soldiers and civilians exposed to frightening events may have unconsciously translated their distress into gastrointestinal disorders. While the nature of army food was initially identified as the cause of duodenal ulcer in servicemen, the pre-war idea that conscientious and anxious individuals were at high risk gathered support and fed into post-war beliefs that this was a stress-related illness. Diet continued to be employed as a means of management at a time when the nation was preoccupied by food because of the constraints imposed by rationing. The peptic ulcer phenomenon set much of the medical agenda for the war years and conflicted with the commonly held view that the British people had never been healthier.