Blood Test Helps IBS Patients Get Firm Diagnosis

A blood test for antibodies against bacterial toxins allows most patients with diarrhea-predominant irritable bowel syndrome (D-IBS) to avoid invasive endoscopies that would otherwise be needed to check for Crohn's disease or ulcerative colitis, a researcher said here. Because IBS symptoms are nonspecific and are also seen in IBD and celiac disease, among others, patients often undergo a long diagnostic odyssey to establish a diagnosis. Pimentel noted as well that IBS is a diagnosis of exclusion, meaning that patients must undergo tests for other conditions that match the symptomatology. In the case of IBD, that typically means repeated colonoscopies. A blood test that would quickly rule out IBD would be a significant benefit to patients by reducing the cost, inconvenience, and discomfort associated with colonoscopies, Pimentel argued. For the trial, Pimentel and colleagues enrolled 2,375 patients with D-IBS diagnosed according to Rome III criteria, along with 142 with IBD, 121 with celiac disease (both also diagnosed according to standard methods), and 43 healthy volunteers. Blood samples were tested with an ELISA assay for anti-CdtB and anti-viculin antibodies.