In patients with ulcerative colitis, alexithymia and related traits were studied using the Karolinska Psychodynamic Profile (KAPP), a recently constructed psychodynamic assessment instrument, and other measures of alexithymia (the Schalling-Sifneos Personality Scale (SSPS) and the Beth Israel Questionnaire (BIQ)), and other personality traits using the Karolinska Scales of Personality (KSP). The results of these measures were analyzed for correlation. The prevalence of mental disorder as defined by DSM-III was not above normal, and the KSP T-scores were within normal limits. As rated with the KAPP, alexithymia was uncorrelated with age or level of education, but was inversely correlated with proximity to a major life event (abdominal surgery), suggesting that alexithymia may have a defensive function. Cluster analysis, with Regression in the service of the ego (R), Alexithymia (A) and Normopathy (N) as clustering variables, yielded 3 groups: normal, multidisturbed (problems with R, A and N) and inhibited (problems with R and N). SSPS failed to distinguish between the multidisturbed and the inhibited groups, and BIQ between any groups. In the multidisturbed group, correlations were found with detachment and with disturbances in interpersonal relations. The results suggest that disturbances in object relations are of major importance in alexithymia.