Sucrose Breath Test to Determine Intestinal Permeability in IBS

The sucrose breath test involves taking by mouth 20 grams of common sucrose. This amount of sucrose is about 4 packets of sugar that you would use to sweeten a beverage. If subjects meet eligibility criteria, a single breath test will be conducted on all subjects. The breath test involves collecting breath by exhaling through a straw into a special test tube. A breath sample is collected before administration of sucrose. After the baseline breath sample, a sugar solution with the 20 grams of sucrose is administered by mouth. Three additional breath samples are collected at 30, 60 and 90 minutes. After 90 minutes, the protocol is finished. We will be analyzing breath carbon dioxide for different levels of heavy carbon atoms (carbon-13)with an instrument called an isotope ratio mass spectrometer. Our study plan is to compare the amount of carbon-13 in breath between IBS patients and subjects without the condition. Up to 20 subjects per group will be studied.