Subgroups of irritable bowel syndrome: a new approach.

OBJECTIVES

The newly revised Rome criteria for the definition of irritable bowel syndrome (IBS), derived from the consensus of experts in the field, were developed in order to identify subgroups of IBS patients for research. The criteria have, to our knowledge, never been validated. Both when trying to include IBS patients in studies and in clinical practice we found it difficult to apply the Rome 2 supportive criteria.

AIM

To study the variation of stool consistency and defecatory symptoms in IBS patients prospectively with diary cards and to validate the Rome 2 supportive criteria.

METHODS

Sixty IBS patients, included by interview according to the Rome 1 criteria, recorded their bowel symptoms on diary cards over 40 days. Four subgroups were found, characterised by loose-stool-predominant, hard-stool-predominant, alternating stool consistency, and loose stools only. Urgency, straining and feeling of incomplete evacuation occurred in all but seven individuals, irrespective of subgroup.

RESULTS

The Rome 2 criteria could subclassify seven patients into diarrhoea-predominant IBS based on stool consistency and absence of straining and could subclassify no patients into constipation-predominant IBS, as urge was present in nearly all patients. Fifty-three patients could not be classified according to the Rome 2 criteria, as they had defecatory symptoms of all kinds.

CONCLUSION

As the Rome 2 supportive criteria use the presence or absence of specific defecatory symptoms as an instrument for categorising IBS patients into diarrhoea- and constipation-predominant subgroups, these criteria could not be used for the majority of IBS patients in this study and should be reconsidered.