Relation among personality and symptoms in nonulcer dyspepsia and the irritable bowel syndrome

The importance of personality traits in nonulcer dyspepsia and irritable bowel syndrome is a controversial issue. We wished to assess the distribution of abnormal personality traits in nonulcer dyspepsia and the irritable bowel syndrome, define any relation among personality and symptoms, and determine whether personality factors discriminate among patients with functional, psychiatric, or organic gastrointestinal diseases. Patients with nonulcer dyspepsia (n = 31), irritable bowel syndrome (n = 67), organic gastrointestinal disease (n = 64), somatoform disorder (n = 36) and healthy controls (n = 128) were studied. Before diagnostic evaluation by an independent physician, all patients completed the Minnesota Multiphasic Personality Inventory and a symptom questionnaire. Symptom scores for abdominal pain and the Manning criteria, which is considered to be diagnostic for the irritable bowel syndrome, were evaluated. Personality scales in patients with nonulcer dyspepsia, irritable bowel syndrome, and organic disease were very similar. However, patients in the other groups differed from somatoform disorder on nearly all scales. In nonulcer dyspepsia, irritable bowel syndrome, and organic disease, hypochondriasis weakly correlated with pain. Subgroups of irritable bowel syndrome patients with predominant constipation and those with predominant diarrhea had similar personality traits, although hypomania was minimally increased in constipation. Patients who fulfilled the Manning criteria for irritable bowel syndrome had more psychological distress than those who did not. The Minnesota Multiphasic Personality Inventory correctly classified somatoform disorder and health 81% and 75% of the time, respectively, but it classified nonulcer dyspepsia and irritable bowel syndrome correctly in only 32% and 34% of cases. Our results suggest that psychopathology may not be the major explanation for functional gastrointestinal disorders.