Two experimental groups of patients with ulcerative colitis (UC) and irritable bowel syndrome (IBS) were compared for hostile personality characteristics and dysthymic states with physically ill patients. Both experimental groups were found to be less dominant, more intropunitive, more anxious and more depressed than the control group. IBS patients, however, were more dominant and less intropunitive than UC patients. Low dominance has been associated with psychosomatic illnesses, and high intropunitiveness with neurotic formation. Both UC and IBS patients have been found to be severely neurotic, a fact reflecting the concurrence of the psychosomatic and neurotic defences in these diseases. More IBS patients had premorbid psychiatric symptoms in comparison with controls and UC patients.