A non-concurrent multi-variate baseline single-case experimental design study (SCED) will be conducted. It will consist of a baseline phase, a treatment phase and a follow up phase, including 6 children and 6 adolescents with their parents.~Participants will be randomly assigned to a baseline length with a duration between 5-15 days.~The design, using a multi-variate baseline, enables each participant to form their own control as outcomes during the baseline are compared with outcomes during treatment. This means that if treatment is effectual a change in outcome measures will show during the treatment period no matter when the treatment period was started.~Outcome will be assessed daily from baseline to end of treatment using electronic self-report questionnaire, with a last, one week long, daily assessment at 3-month follow-up.~The questionnaire is designed for this specific study and consist of 8 items (modified to a daily question) from validated questionnaires, the scale is changed to an 11 point scale from 0(not at all) to 10(all the time) Outcome are: abdominal symptoms (2 items from PedsQL Gastro 9 items questionnaire), symptom catastrophizing (2 items from Visceral Short sensitivity Index questionnaire), avoidance and control behavior (2 items from IBS Behavioural Response Questionnaire), and symptom acceptance(2 items from Chronic Pain Acceptance Questionnaire for Adolescents 8-items)~In addition, a more comprehensive battery of questionnaires will be completed by the children and adolescents and the parent, respectively, at baseline, mid-treatment, end of treatment and at 3-month follow-up.
Functional gastrointestinal disorders (FGID) are common among children and adolescents. They affect quality of life, cause functional disability, school absence and high health care use. Despite this there is a lack in treatment options.~The aim of the current study, embedded in The Danish FGID Treatment Study, is to investigate the detailed course of efficacy of Danish versions of Swedish Internet based cognitive behavioural therapy (i-CBT) programs for children and adolescents with FGID in a Danish clinical context. This will be done using a single case design study. Along with this, the impact of parental illness worries will be investigated.