International Psychometric Validation Study of the Intestinal Gas Questionnaire (IGQ)

Observational (non-interventional) study with a cross-sectional part for a subset of adult subjects with a single IGQ completion and a longitudinal cross-over part for a subset of subjects with test-retest IGQ completion for validation of electronic version of IGQ.

300 eligible subjects (100 in each of the 3 countries: France, UK & Spain):

• 180 with IBS diagnosis (60% of recruited subjects)
• 120 from General population (40% of recruited subjects)

Inclusion criteria

All (subjects with IBS diagnosis and general population):

• Complaining of gas-related symptoms (GRS) of a certain severity level: subjects with IBS diagnosis and general population need to report a score of 4 or greater on at least one symptom on the symptom screening tool
• Cognitive and linguistic capability to complete several self-questionnaires
• BMI > 18.5 and < 30.0 kg/m2
• Agreement of the subject to participate in the study

Subjects with IBS diagnosis:

• IBS diagnosis using Rome III diagnostic criteria for Functional Gastrointestinal Disorders (21)
• IBS severity: IBS-SSS score of 75 to 300

General population:

• Subjects not fulfilling IBS Rome III criteria
• Regular stool frequency (i.e., between 3 and 21 bowel movements per week)

Exclusion criteria

All (subjects with IBS diagnosis and general population):

• Recent (2 last weeks) change in diet or intake of potentially flatulogenic compounds (fiber, lactulose)
• Organic gastrointestinal disease
• Other functional gastrointestinal disorder as defined by Rome III criteria
• Any severe and progressive disease (e.g. depression, cancer, uncontrolled diabetes, rheumatoid arthritis…)
• Any severe psychiatric disorder (e.g. acute episode of schizophrenia or bipolar disorder…)
• Pregnant women
• Being under the direct hierarchy of the investigatorBelonging to the site's staff team

General population:

• Treatment for diarrhea or constipation including lactulose