Colas, Juices May Be Common Culprits in Intestinal Distress

From the WebMD Archives

Oct. 22, 2001 -- For some people, beans and other fiber-rich foods are troublemakers. To others, it's milk and ice cream. But millions of Americans who suffer from chronic, painful bloating and gas don't know what triggers their intestinal insurrections.

It turns out that for many, sugars commonly found in fruits, sodas, and honey may not be so sweet. New research suggests that a large number of people with frequent and unexplained gas and bloating suffer from a condition similar to lactose intolerance. But rather than being unable to digest milk products, they are unable to digest fructose.

"Fructose intolerance appears to be a common problem in patients with otherwise unexplained gastrointestinal symptoms," says researcher Young K. Choi, MD, of the University of Iowa. Many of these people, Choi adds, fit the criteria for irritable bowel syndrome, or IBS.

Choi is scheduled to present his findings on fructose intolerance Wednesday at the 66th annual scientific meeting of the American College of Gastroenterology in Las Vegas.

More than one in 10 Americans are believed to suffer from IBS, although many never seek medical help for the problem. Symptoms of the condition can include frequent cramping, gas, bloating, and either constipation or diarrhea. For some sufferers, those symptoms can be mild and intermittent, but for others they can be daily and life altering.

In their study, Choi and colleagues included 219 people who had sought medical help for unexplained gas, bloating, and abdominal pain. All underwent fructose breath tests before and after they ingested about two ounces of the sugar. Breath samples revealed that in nearly four out of five participants, there were abnormal levels of hydrogen or methane gas present. More than half of the study participants also experienced significant gas and bloating after they ingested the fructose.

Choi says that it will take further research to determine the precise nature of the relationship between fructose and intestinal distress. But until then, doctors need to be able to recognize the problems, since limiting fructose in the diets of affected patients could help bring some relief.


In addition to fruits, juices, and honey, processed foods made with corn syrup are high in fructose. Most soft drinks are now made with varieties of corn syrup instead of cane sugar, as are many types of chewing gum.

GI specialist Peter McNally, DO, says the lessons learned from treating lactose intolerance show that dietary restrictions can make a difference. The University of Colorado professor of medicine says the best studies show that lactose intolerance occurs in roughly 30% of people with IBS, and that symptoms resolve in about 40% of those who eliminate dairy products from their diets.

"Just like lactose intolerance, you can test for fructose intolerance with a simple blood test," he tells WebMD. "And it may be that by making dietary modifications people can resolve these symptoms. This is a relatively new idea, although I think most gastroenterologists are aware of it. Most primary-care doctors may not be, but studies like this one may help make them more aware."