Psychology / Immunology / Psychometrics / Quality of life / Adolescent / Humans / Female / Male / Clinical Sciences / Middle Aged / Questionnaires / Adult / Public health systems and services research / Gastrointestinal Tract / Reproducibility of Results / Pain Measurement / Humans / Female / Male / Clinical Sciences / Middle Aged / Questionnaires / Adult / Public health systems and services research / Gastrointestinal Tract / Reproducibility of Results / Pain Measurement