Nov. 12, 2015 -- Food allergies and genes that raise your odds of getting allergic diseases might play roles in some people's irritable bowel syndrome (IBS), two new studies suggest.

Allergic asthma, rhinitis, and eczema go hand-in-hand with diarrhea and bad digestive reactions to food in certain people with IBS, researchers say.

"The thinking is that if you can figure out their food allergies, you can really improve their diarrhea and abdominal pain. And we see in the clinic that they do feel better," says senior researcher Mary Tobin, MD, an allergist at the Rush University Medical Center in Chicago.

The findings of both studies were presented at the American College of Allergy, Asthma, & Immunology 2015 Annual Scientific Meeting.

In one study, Tobin and her colleagues spotted a possible connection between allergic rhinitis, asthma, and the allergic gut.

They evaluated 122 with people with IBS tied to allergies and 32 with IBS and no allergies. Those with IBS associated with allergies were more likely to have diarrhea as their main problem. And those with IBS and no allergies were more likely to have constipation as their main symptom.

The diarrhea is possibly from reactions that are similar to what happens with food allergies, Tobin says.