Discrepancies between reported food intolerance and sensitization test findings in irritable bowel syndrome patients

OBJECTIVE: irritable bowel syndrome (IBS) is a common gastrointestinal diso rder with clinical signs typical of "intestinal" food allergies or intolera nce. The aim of this study was to characterize the clinical features or IBS patients suspected of suffering from adverse reactions to food. METHODS: The study involved 128 consecutive IBS patients divided into four groups according to their main symptom on presentation at our outpatient cl inic. A detailed medical history was recorded, paying particular attention to any allergies and reported intolerance to food. Each patient was screene d for allergies; intestinal permeability tests was performed in randomly se lected patients from different groups. Findings were analyzed using the chi (2) test. RESULTS: Adverse reactions to one or more foods were reported by 80 patient s (62.5%); skin prick tests (SPT) were positive in 67 patients (52.3%) with no significant differences between patients complaining of different sympt oms. Patients who reported a food intolerance had more positive SPTs than t hose who did not (47 of 80 [58.7%] vs 20 of 48 [41.7%]); this difference wa s not statistically significant, although it suggests a trend (p < 0.0610). There was little consistency between the specific foods reported to cause intolerance and those resulting from the tests (11 of 80 patients, 13.7%). The intestinal permeability test was normal in 29 of 33 patients (87.9%). CONCLUSIONS: More than 50% of IBS patients were found sensitized to some fo od or inhalant without any typical clinical signs. Patients were unable to identify potentially offending foods. The lack of a correlation between SPT results and reported food allergies needs further investigation to clarify the pathophysiology and improve the diagnosis of intestinal food allergies . (Am J Gastroenterol 1999; 94:1892-1897, (C) 1999 by Am. Cell. of Gastroen terology).