Gastrointestinal Symptoms in Healthy Subjects and Patients With Irritable Bowel Syndrome

Inclusion Criteria: * for Healthy subjects : * Healthy women and men free-living subject aged from 18 to 65 years. * Subject with a body mass index between 18 and 30, bounds included. * Subject having given written consent to take part in the study. * Chronic medical treatment-free excluding contraceptive and stable Hormonal Replacement Therapy * for IBS Patients : * IBS women and men free-living subject aged from 18 to 65 years * Subject with a diagnosis of IBS according to Rome III criteria: recurrent abdominal pain or discomfort at least 3 days per month in the last 3 months associated with 2 or more of the following: improvement with defecation; onset associated with a change in frequency of stool; onset associated with a change in form (appearance) of stool. * Subject with a diagnosis of IBS according to Rome III criteria with symptom onset at least 6 months prior to diagnosis. * Subject having an IBS-SSS score higher or equal to 75 corresponding to an active phase of IBS symptoms. * Subject having given written consent to take part in the study. Exclusion Criteria: * for Healthy subjects : * Subject who, in the past, has consulted a general practitioner or a gastroenterologist for (IBS) or any other functional bowel disease including constipation and diarrhoea. * Subject with known organic disease, including an inflammatory bowel disease, a benign or malign tumour of intestine or colon and significant systemic disease * Subject treated with any chronic medical treatment that, in the investigator's opinion could interfere with the GI tract. * Subject who underwent general anaesthesia in the preceding 4 weeks. * Pregnant subject or breast-feeding subject at the time of the study. * Subject with known immunosuppression * Subject with any known food allergy * Subject involved in any other clinical study within the preceding month or in exclusion period after another clinical study. * Subject in a situation, which in the investigator's opinion could interfere with optimal participation in the present study or could constitute a special risk for the subject. * Subject not able to read, to understand and/or to answer to the questionnaires. * for IBS Patients : * If a subject fulfils with one of the following criteria, he/she must be excluded from the study: * Subject with a diagnosis of IBS with clinical signs of alarm (rectorragy, fever, associated inflammatory articular signs, recent weight loss). * Subject with known organic disease, including an inflammatory bowel disease, a benign or malign tumour of intestine or colon and significant systemic disease. * Subject who underwent general anaesthesia in the preceding 4 weeks. * Pregnant subject or breast-feeding subject at the time of the study. * Subject involved in any other clinical study within the preceding month or in exclusion period after another clinical study. * Taking antidepressant or analgesic drugs. * Subject not able to read, to understand and/or to answer to the questionnaires.