Background: A discrepancy between recalled and recorded bowel habit subtypes has been reported in irritable bowel syndrome (IBS), but the reasons for it remain unclear.
Aim: To assess the agreement between recalled and recorded bowel habit subtypes; to determine whether any discrepancy is related to stool form variability or psychological factors; and to test the correlations of recalled and recorded stool form with colonic transit time.
Methods: Bowel habit subtype was established in 54 IBS patients at the enrolment visit (recalled) and with the aid of diary cards (recorded). Colonic transit time, the variability of stool form and the patients' psychological profiles were also recorded.
Results: Recalled and recorded bowel habit subtypes agreed in only 54% of the patients (kappa = 0.28). Stool form variability was greater among the patients whose recalled and recorded bowel habit subtypes were discordant (P = 0.03), whereas the psychological profiles were not different. Colonic transit time significantly correlated with stool form only when it was recorded on diary cards.
Conclusion: The discrepancy between recalled and recorded bowel habits in IBS patients is related more to stool form variability than an altered psychological profile. Diary cards should be used to ensure that stool form reflects colonic transit time.