Forty patients with a diagnosis of irritable bowel syndrome (IBS) and 32 patients with peptic ulcer disease underwent a full psychiatric assessment. All were rated using the Gastrointestinal Symptom Rating Scale (GSRS), the Comprehensive Psychopathological Rating Scale, the Life Experiences Survey and the Eysenck Personality Inventory. The 2 groups were not distinguishable on total GSRS scores or rates of DSM-III diagnosed mental disorder. However, greater trait scores for neuroticism and introversion were found in the IBS group, together with a greater reporting of life events perceived as negative.