Gastrointestinal and mental symptoms were assessed in 101 outpatients with the irritable bowel syndrome (IBS). A normal female population was used for comparison of mental symptoms. By definition all patients had abdominal pains and/or change of bowel habits (constipation or diarrhoea, or both) but no demonstrable organic disease. Upper gastrointestinal symptoms without peptic ulcer disease were reported by 87% of the patients. Mental symptoms were reported by almost all patients. Symptoms of anxiety, fatiguability, hostile feelings, sadness, and sleep disturbances were seen significantly more often among IBS women than in the controls. We conclude that patients with IBS frequently have upper gastrointestinal and mental symptoms that should be taken into account in the therapeutic management and evaluation of new modes of treatment.