Despite the fact that food and diet are central issues, that concern patients with irritable bowel syndrome (IBS), the current understanding about the association between the intake of certain foods/food groups and the gastrointestinal (GI) symptom pattern, psychological symptoms, and quality of life is poor. The aim of this study was to determine which food groups and specific food items IBS patients report causing GI symptoms, and to investigate the association with GI and psychological symptoms and quality of life.