Abstract

Hans Selye in a note to Nature in 1936 initiated the field of stress research by showing that rats exposed to nocuous stimuli responded by way of a "general adaptation syndrome" (GAS). One of the main features of the GAS was the "formation of acute erosions in the digestive tract, particularly in the stomach, small intestine and appendix". This provided experimental evidence for the view based on clinical data that gastro-duodenal (peptic) ulcers could be caused by stress. This hypothesis was challenged by Marshall and Warren's Nobel-prize (2005) winning discovery of a causal association between Helicobacter pylori and peptic ulcers. However, clinical and experimental studies suggest that stress can cause peptic ulceration in the absence of H. pylori. Predictably, the aetiological pendulum of gastric and duodenal ulceration has swung from 'all stress' to 'all bacteria' followed by a sober realisation that both factors play a role, separately as well as together. This raises the question as to whether stress and H. pylori interact, and if so how? Stress has also been implicated in inflammatory bowel disease (IBD) and related disorders: however, there is no proof yet that stress is the signal aetiological trigger for IBD. Central dopamine mechanisms seem to be involved in the stress induction of peptic ulceration, while activation of the sympathetic nervous system and central and peripheral corticotrophin releasing factor appear to mediate stress-induced IBD