FRIDAY, Oct. 28 (HealthDay News) -- A quarter of patients with irritable bowel syndrome (IBS) have food hypersensitivity (FH), which can be detected using fecal assays; most accurately with eosinophil cationic protein (ECP) assay, according to a study published in the November issue of Clinical Gastroenterology and Hepatology.
Antonio Carroccio, M.D., from the University of Palermo in Italy, and colleagues investigated the frequency of FH in patients with symptoms of IBS, and the ability of fecal assays for tryptase, ECP, or calprotectin to diagnose FH. A cohort of 160 patients with IBS, 40 patients with other gastrointestinal diseases, and 50 healthy control individuals completed a symptom severity questionnaire at the start of the study. Fecal samples were assayed and the levels of specific immunoglobulin E were assessed. Participants were observed for four weeks, then placed on an elimination diet for four weeks, during which time they kept a diet diary. Based on the results of an oral food challenge, participants who reported improvements after the elimination diet period were diagnosed with FH.
The investigators found that 25 percent of the patients with IBS had FH. Significantly higher levels of fecal ECP and tryptase were found in patients with IBS and FH than those without FH. The most accurate assay for diagnosis of FH was the ECP assay, with 65 percent sensitivity and 91 percent specificity.
"A relatively high percentage of IBS patients are actually suffering from FH," the authors write. "Fecal assays of ECP may be useful in identifying FH patients among IBS-presenting subjects."