Investigating chitin-glucan for Crohn's disease patients with IBS-like symptoms

Inclusion Criteria:

* Male and female patients aged from 18 years to 75 years,
* Long standing (\>3 months prior to V1) steroid-free clinical remission Crohn's disease according to clinical and biochemical assessments,
* Clinical remission (according to the investigator),
* Absence of inflammatory markers at V1,
* Presence of IBS-like symptoms according to Rome IV criteria,
* Likert scale ≥ 3 for abdominal pain at V0,
* Patient with correct and complete reporting of the study questionnaires and scores during the run-in period (≥ 75% completion),
* To continue all medication used in the last month before inclusion at the same dosage,
* Anti-spasmodic, hypomotility agents, probiotics, prebiotics, bile-acid chelators, and anti-depressants are authorized if consumed for longer than 1 month before inclusion and maintained at a stable dosage for the entire study duration,
* Agreeing to maintain their lifestyle behaviours during the participation in the study,
* Patient has read, understood, and signed the informed consent form (ICF),
* Patients capable of communicating with the investigator, replying to the questionnaires, and understanding the requirements and constraints of the study protocol,
* Possession of a digital device (i.e., smartphone or tablet),
* Patient willing to adhere to the study visit schedule and able to understand and comply with protocol requirements and product administration,
* Male or female patient of childbearing potential who agrees to use acceptable methods of birth control (oral, transdermal, systemic contraception, intrauterine device, condom) for the duration of the study,
* Patient can read and write in French.

Exclusion Criteria:

* Patients with other concomitant organic gastrointestinal abnormalities besides Crohn's disease: ano-perineal lesions, extra-intestinal manifestations of Crohn's disease, colorectal history of cancer or abdominal radiotherapy, symptomatic intestinal stenosis, substance dependence history,
* Patients with significant comorbidities: instable cardiovascular diseases, complicated diabetes, instable thyroid function,
* Patients receiving non-steroidal anti-inflammatory drugs, steroids, opioids, or narcotic analgesics in the last month before V0,
* Patients beginning a diet or a specific treatment for functional symptoms (probiotics, prebiotics, anti spasmodic, chelators, anti-depressants, etc.) within one month before V1,
* Ongoing antibiotics or antibiotics prescribed in the last 2 weeks before V1.
* Excessive alcohol consumption (\>30 g/day \[i.e., 3 units/day\] for men and \>20 g/day \[i.e., 2 units/day\] for women) and/or drug abuse,
* Pregnancy and lactation, or plan to become pregnant during the study period,
* Participation in other studies involving investigational or marketed products concomitantly or less than 3 months prior to V0,
* Known hypersensitivity to any of the ingredients or excipients of the study products,
* Patient who has forfeited their freedom by administrative or legal award, or who is under guardianship or under limited judicial protection.