Irritable Bowel Syndrome And Fructose

Irritable Bowel Syndrome

Irritable bowel syndrome or IBS is a digestive condition characterized by abdominal pain and/or changes in bowel habits. Patients may report stomach cramps, bloating, abdominal distension, and an urgent need to defecate. Pain is often relieved after using the bathroom. The symptoms may be accompanied by diarrhea, constipation, or alternating cycles of diarrhea and constipation. Those with diarrhea may experience small, loose stools sometimes accompanied by passage of mucus.

IBS is the most common condition seen by primary care physicians and gastroenterologists, accounting for more than three million office visits each year. According to the Irritable Bowel Syndrome Self Help and Support Group, the condition affects 10 to 20 percent of Americans. Roughly 70 percent of patients are females. Almost all patients are diagnosed by 50; in roughly half, the symptoms appear before 35.

The range of IBS symptoms varies. Some patients have mild symptoms, while for others, the condition is quite disabling. Research shows IBS patients miss three times as many work days as people without the condition. Those with severe symptoms may be unable to leave the house, even for short periods of time.

The Role of Fructose

Researchers have found certain medications and foods can trigger the symptoms of IBS in susceptible people. Some of those triggers include chocolate, milk products, alcohol, and caffeine. Some women with IBS report an increase in symptoms during their menstrual cycle.

Investigators are also looking into another potential culprit – fructose. Fructose is a simple sugar found in honey and certain fruits. It is much sweeter than sucrose (cane sugar) and often used as a sweetener in foods and beverages. Some people are unable to absorb the sugar and it passes into the stomach. Here, bacteria break down the sugar into short fatty acids, carbon dioxide, and hydrogen. In turn, that produces bloating, cramps, diarrhea, and other signs of indigestion.

Researchers believe fructose may play a role in IBS symptoms as well. To test their theory, investigators are comparing fructose metabolism in patients with IBS against those without the condition. First, participants drink a liquid containing fructose. Then, periodically over the next three hours, patients will take a breath test to measure fructose metabolism. The test measures levels of hydrogen in the breath sample. People who don't metabolize fructose will have higher levels of hydrogen in the breath. The researchers are testing the response to three different amounts of fructose concentration – 25 grams, 50 grams, and 37.5 grams (roughly the equivalent of three cans of soda). Investigators will also log any symptoms experienced throughout the test period.

If a patient is found to react adversely to the fructose (develop IBS symptoms), avoidance of foods and drinks with the substance may greatly improve symptoms. In addition, patients may be able to reduce the amount of medication needed to control their symptoms. The fructose and IBS study is being conducted at Temple University Hospital in Philadelphia and is still accepting study volunteers. For more information, contact study coordinators at 215-707-5477.

The study is being conducted at Temple University Hospital in Philadelphia, PA and is still accepting study volunteers. For more information, contact study coordinators at 215-707-5477.

For general information on Irritable Bowel Syndrome:

American College of Gastroenterology, 4900 B South 31 St. Arlington, VA 22206,

Irritable Bowel Syndrome (IBS) Self Help and Support Group, 1440 Whalley Avenue, #145, New Haven, CT 06515,

National Digestive Diseases Information Clearinghouse, 2 Information Way, Bethesda, MD 20892,