This is an unicenter, prospective, proof-of-concept randomized controlled, non-blinded intervention study that focuses on two patient populations, with overlapping symptom patterns and treatment approaches, i.e. patients with IBS and IBD-IBS.

Following written informed consent, the eligibility screening is performed and instructions about the study procedures will be given. Hereafter, both groups will independently be randomized into i) an ESM/Traqq arm or ii) a standard care arm. The intervention group and the control group will complete the IBS-SSS, EO-5D-5L, GAD-7, PHQ-9, VSI, and MFl-20 as well as the Rome IV criteria for IBS and functional dyspepsia at baseline and the intervention group will complete thereafter the ESM and Traqq applications during the first week. After this week, the data will be analysed to identify associations between abdominal pain and psychosocial factors, diet or other GI associated symptoms. About two weeks later, participants will have their second visitation at the outpatient clinic with their treating physician. In the intervention group, but not the control group, the patient and the treating physician will receive the results of the personal data of the patients based on ESM and Traqq. The insight participants and their physicians get from this information, will help them to make changes in lifestyle factors that affect their symptoms or to choose a pharmacological or non-pharmacological treatment. However, the study protocol will not indicate which treatment choice should be made by the patient and their treating physicians. That choice will still be based on shared decision making, just as in the standard care arm, only with the additional data provided. Furthermore, if the patients are referred to a dietician, psychologist, or both, the digital data obtained in the intervention group can be used to personalize the therapy. After giving informed consent by the participant for the data of ESM and Traqq being sent to the dietician or psychologist they are referred to, the coordinating investigator will send the data digitally to the dietician or psychologist that is needed for the personalized treatment. Participants in the control arm will get a consultation with the gastroenterologist as usual after the same period of time as the intervention group get their consultation. The participants of the control group will be given treatment advice only based on this consultation, the PDSkeuzehulp by shared decision making, according to standard care. Twelve weeks after the second outpatient visit, independently of the chosen treatment approach, the participants in both study groups will be asked to complete IBS-SSS, EQ-5D-5L, GAD-7, PHO-9, VSI, MFI-20 and Rome IV criteria for IBS and functional dyspepsia for the second time to evaluate whether there is an effect on 1) reduction of abdominal pain and 2) quality of life, psychological aspects or fatigue of the participants due to the insight provided by ESM and Traqq.

After those twelve weeks, the coordinating investigator will contact the participants of the intervention group and control group by phone for the last time. Participants are asked what treatment they have gotten and what lifestyle modifications they have done to reduce abdominal pain. To improve compliance for completing the questionnaires by the control group, the participants in the control group will get the opportunity to use the ESM and Traqq applications after the study has been completed. This will not be part of this study but can be beneficial for those individuals who have not got any additional insight about their symptoms by getting the standard care.