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IBS symptoms and quality of life 61 3 patients who do not meet the diagnostic criteria after a follow-up period is thus in line with the findings of this follow-up study in our Dutch cohort. Given that clinical treatment decisions often rely on prognostic predictions of the disease course, we sought to identify baseline predictors for a less favorable disease course. This study, however, did not show any baseline characteristics associated with meeting the Rome III criteria at follow-up. As IBS is a highly heterogeneous disorder, larger study populations might be necessary to investigate what factors influence and thereby predict the natural disease course in (subgroups of) patients with IBS. Rather unexpectedly, we found that a decrease in GI symptom severity did not lead to an improved quality of life in our study. Clevers et al. recently evaluated longitudinal symptom changes over time and, in contrast to our results, found that patients with lower GI symptom severity had significantly higher quality of life scores. 37 They also demonstrated that GI-specific anxiety is associated with an increase in GI symptom severity, which is in agreement with our results as GI-specific anxiety was significantly lower in the group that did not fulfill the Rome III criteria. The inconsistency between our data in terms of quality of life might be explained in part by the different questionnaires used. Clevers et al. used an IBS specific questionnaire, the IBS-QoL 38 , which assesses more disease specific changes in quality of life in contrast to generic quality of life instruments, such as the SF-36 that we used. Our data can therefore also be compared with other diseases and with the general population. Both the Rome III- positive and -negative group showed lower mean quality of life than the mean of a Dutch population sample 39 and of a USA based population without a functional GI disorder. 40 Additionally, we used the validated SWLS to score overall life satisfaction. This has been used in healthy persons and in patients with Crohn’s disease 41 , but, to our knowledge, not in IBS patients. We found scores comparable to the ones reported by Crohn’s disease patients for both the Rome III-positive and -negative group. In contrast to GI symptom severity, we found that quality of life did not improve over time in those that were Rome III-negative at follow-up. The data reported here suggest that concurrent, but not baseline, psychological comorbidities are more predictive of this impaired long-term quality of life than GI symptom severity. Several studies in IBS have found similar results, in particular for the mental health related quality of life; i.e. Naliboff et al . reported that psychological distress had a stronger effect on health related quality of life than GI symptoms 42 , Koloski et al . reported that depression was independently associated with mental quality of life 43 , and Addante et al. reported that perceived stress, and anxiety and depression were significant predictors for mental