Irritable Bowel Syndrome Diagnosis: The Rome III Criteria

Engsbro AL, Begtrup LM, Kjeldsen J, et al. Patients suspected of irritable bowel syndrome-cross-sectional study exploring the sensitivity of Rome III criteria in primary care. Am J Gastroenterol. 2013;108:972-980.

Taken at face value, this Danish study appears to endorse the Rome III criteria as a useful tool in the diagnosis of irritable bowel syndrome (IBS). The authors found that a Rome III questionnaire had a 75% sensitivity for IBS, using a primary care clinical diagnosis as the gold standard.

But the picture is more complex. I found it useful to read the study in the context of the recent report from the Multinational Irritable Bowel Syndrome Initiative (MIBSI). The MIBSI panel, composed of international experts in IBS, took issue with a key element of the Rome III criteria: the centrality of pain or discomfort as a diagnostic criterion for the condition. The MIBSI panel asserted that pain is not a central feature of IBS and suggested that future standards should de-emphasize pain and include bloating as a key diagnostic criterion.

So one could view the Danish study as simply confirming that primary care physicians have internalized some version of the Rome III criteria and are, in MIBSI’s view, overemphasizing pain in the diagnosis of IBS. The MIBSI paper suggested that they are likely missing another cohort for whom bloating is predominant. Primary care providers may simply be employing a clinical gestalt that gives similar diagnostic yield as strict Rome III criteria.

The Danish study incorporated Rome III into a patient questionnaire and for an IBS diagnosis to be made required abdominal pain or discomfort for at least 3 days per month in the past 3 months, associated with at least 2 of the following: (1) improvement with defecation, (2) onset associated with a change in stool frequency, and (3) onset associated with change in appearance of the stool.

The study included 499 patients; all had been referred into the study from primary care practices where they had been given a diagnosis of IBS. No diagnostic criteria were required for referral into the study, only the primary care physician’s label of IBS.  

As above, 75% of patients labeled with IBS by a primary care physician satisfied the Rome III criteria as administered in the questionnaire. Rome III–positive patients had a higher symptom burden and lower health-related quality of life.

One interesting piece of data that the study did not collect was the likelihood that Rome III–negative patients were defined as non-IBS by their primary care physician. In other words, this study looked only at sensitivity, not specificity.
 
But the key limitation here is that physician gestalt is not a gold standard against which other diagnostic tests can be measured-this study simply confirms that primary care is not far off from the current international (gestalt-based) standard for this diagnosis.

Perhaps the more useful tidbit for primary care is that Rome III (or whatever superior standard is eventually adopted) can be effectively administered as a questionnaire that would pick up three-quarters of the cases.