Irritable Bowel Syndrome and Food Sensitivity

Inclusion Criteria: * Between 18-70 years of age. * Irritable Bowel Syndrome by Rome III criteria. * Stable dose (30 days) of concurrent IBS medications * Agree not to make significant changes to their diet during the study * IBS-SSS score of \>150 Exclusion Criteria: * History of major abdominal surgeries * History of inflammatory bowel disease * Antibiotic use within 1 month of enrollment * Radiation proctitis or other known poorly controlled medical conditions that could interfere with bowel function * Current use of opioid pain medications (except for NSAIDs) * Previous experience participating in dietary studies for IBS * Current use of medications which are known to be affected by modest dietary changes * Vitamin C use of \>2000 mg/day * Quercetin use of \>500 mg/day