Inclusion Criteria:  IBS according to ROME IV criteria (with diarrhoea)  Exclusion Criteria:  Celiac disease or any other gastroenterology disease (such as inflammatory bowel disease, celiac disease, microscopic colitis, diverticulitis, radiation enteritis). Suspected or known strictures, fistulas or physiological/mechanical GI obstruction, history of gastric bezoar. Appendicectomy and cholecystectomy <3 months. Heart-, liver-, neurological-, or current psychiatric disease, diabetes, obesity (BMI>30), other disease or surgery to the abdomen that affected intestinal function. Implantable or portable electro-mechanical medical devices, e.g. pacemakers. Swallowing disorders/dysphagia to food or pills. Allergy or intolerances to foods. Compliance to a special diet (including vegan, vegetarian, gluten-free or low FODMAP diet). Pregnant or breast feeding. Usage of antibiotics within 4 weeks prior to inclusion Usage of alcohol more than 14 units per week. No new pharmacological treatment during the study period. Medications: laxatives, neuromodulators or opioids (morphine, codeine, tramadol…)