FAIS trial; Faecal transplantation in Adolescents with refractory Irritable bowel Syndrome

INTERVENTION: Bowel lavage with Klean‐Prep Faecal transplantation by nasoduodenal tube infusion Venapunction CONDITION: Irritable bowel syndrome, Adults, Feces, Transplantation ; ; PRIMARY OUTCOME: To investigate the effect of repetitive healthy donor faeces infusion (allogeneic) in comparison to infusions with own faeces (autologous) on decrease in IBS complaints, assessed with the pain component of the Irritable Bowel Syndrome Severity Scoring System (IBS‐SSS) score SECONDARY OUTCOME: To investigate the effect of two healthy donor faeces infusion (allogeneic) in comparison to two infusions with own faeces (autologous) on: ; ; 1. Intra‐individual changes in faecal gut microbiota composition ; ; 2. Safety of faecal microbiota transplantation in patients with irritable bowel syndrome ; ; 3. Decrease in IBS complaints, assessed by abdominal pain frequency and intensity, after 6 and 12 months ; ; 4. Total IBS‐SSS score ; ; 5. Health‐related quality of life (HRQOL) ; ; 6. Depression and anxiety scores ; ; 7. Adequate relief ; ; 8. Absence of school or work, use of health care resources and additional costs ; 9. Safety parameters ; ; ; INCLUSION CRITERIA: Patients • Age 16‐21 years • Non‐smokers • Ability to give informed consent • Established irritable bowel syndrome diagnosis according to the Rome IV criteria for children or adults o Before inclusion, all patients undergo routine laboratory testing to exclude underlying organic disorders: complete blood cell count, C‐reactive protein, celiac screening (anti‐transglutaminase antibodies and IgA), and faecal calprotectin. The need for further diagnostic testing is left to the discretion of the treating physician. • According to a recently published guideline by the Rome Foundation for the design of pharmacological clinical trials in adolescents, patients are required to have an average daily pain rate of at least 30mm on the pain component scale of the IBS‐SSS • Symptoms are present for = 12 months • The patient has received adequate explanation and reassurance for his/her symptoms