IBS occurs in about 15 percent 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.

"The reported presence of allergic dermatitis was highly correlated to the presence of IBS in our population," the study authors wrote. "In atopic disease, allergic dermatitis is the first step of the 'atopic' march.' In early childhood, AE (allergic eczema) is frequently associated with gastrointestinal dysfunction and food allergy. A clinical history of AE may be a useful marker for patients with gut hypersensitivity and atopic IBS."

The researchers also found that asthma and IBS were reported by 12 of 41 patients (29 percent), similar to findings in a previous study. The researchers proposed that "this subgroup of IBS (atopic IBS) be considered separately from patients with IBS without atopic symptoms, because they may have distinct pathophysiologic features and may benefit from specific therapeutic interventions."

The study was published recently in the Annals of Allergy, Asthma & Immunology.

More information

The U.S. National Institute of Diabetes and Digestive and Kidney Diseases has more about IBS.

SOURCE; American College of Allergy, Asthma & Immunology, news release, January 2008

-- Robert Preidt