Brachyspira and Intestinal Allergy-like Immune Reactions in Patients With Irritable Bowel Syndrome (IBS)

The aim of this study is to define local immune responses in the GI tract to food antigens in IBS patients, with and without Brachyspira infection, using advanced imaging. We hypothesize that Brachyspira infection can cause IBS symptoms by inducing loss of oral tolerance to dietary antigens through development of food-specific intestinal immune reactions and subsequent development of visceral hypersensitivity. During this study, the investigators will perform confocal laser endomiscroscopy (CLE) and/or colonoscopic antigen provocation test (COLAP) to test to which food items the participants react to. Furthermore, the investigators will perform rectal barostat examination and a sigmoidoscopy without laxatives. The investigators will collect biological samples and the participants will complete several questionnaires.