There may be a link between allergies and irritable bowel syndrome (IBS) in adults, says a study by researchers at Rush University Medical Center in Chicago. IBS occurs in about 15% of the U.S. population. Some studies have suggested that allergen exposure may lead to IBS symptoms in some patients, but the frequency hadn't been examined. In this study, researchers looked at 125 adults and found the likelihood of IBS was much higher in patients with allergic eczema (3.85 times) and seasonal allergic rhinitis (2.67) times. They also found that IBS was 2.56 times more likely in people with depression.