The diagnosis of irritable bowel syndrome requires the exclusion of any associated organic disease: a positive diagnosis would avoid expensive and potentially dangerous diagnostic procedures. A scoring system has been proposed for positive diagnosis where more than 44 points excluded organic digestive disease. The aim of this study was to determine the usefulness of this scoring system in a different setting. Patients (1257) consecutively referred to our medical division were admitted to the study and 270 of these, complaining of abdominal symptoms, were scored on the Kruis system method. The positive predictive value (53.8% for men and 81.5% for women) and the sensitivity (46.7% and 59.5%) did not appear to be adequate. The negative predictive value (91.6% and 87.3%) and the specificity (93.5 and 95.4%) gave higher results, but two cases of neoplasia and nine cases of other organic digestive diseases were not identified or suggested. We believe that this scoring system may be useful only as a first step in a diagnostic flow chart.