Studies suggest that the positive predictive value of the Rome II diagnostic criteria of irritable bowel syndrome (IBS) can be enhanced by excluding red flag symptoms suggestive of organic diseases.
Dr Whitehead and colleagues assessed the utility of red flags for detecting organic diseases in patients diagnosed with IBS by their physicians.
The team completed systematic chart reviews in 1434 patients with clinical diagnoses of IBS, abdominal pain, diarrhea or constipation.
The patients also completed questionnaires to identify Rome II criteria for IBS and red flag symptoms.
The researchers found that the overall incidence of gastrointestinal cancer was 3%, and 1% in those with IBS.
|Red flag inclusion left 84% without an IBS diagnosis|
|Alimentary Pharmacology & Therapeutics|
The overall incidence of inflammatory bowel disease was 2%, but only 1% in IBS.
The team noted that the incidence for malabsorption was just over 1% overall, and was under 1% in IBS.
Red flags were reported by 84% of the sample.
The researchers observed that the positive predictive value of individual red flags for identifying organic disease was 7% to 9%.
Excluding any patient with a red flag improved the agreement between Rome II and clinical diagnosis by a modest 5%.
However, the team noted that this left 84% of patients who were diagnosed with IBS by their physicians, without a diagnosis.
Dr Whitehead's team concluded, “Red flags may be useful for identifying patients who require additional diagnostic evaluation.”
“To incorporate them into the Rome criteria would not improve sensitivity and would result in too many missed IBS diagnoses.”