Setting up a Cohort of Patients With Inflammatory Bowel Disease and a Cohort of Patients Without Chronic Inflammatory Bowel Disease

Inclusion Criteria: General criteria: * Male or female ≥ 18 years old * Able to follow the instructions of the study * Having signed an informed consent Specific for Crohn cohort: * A confirmed diagnosis of IBD * Rectal or colonic or ileocolic involvement * Patients with CD presenting inflammatory flare and disease extent in the colon or ileocolic region with: * A clinical activity defined by an average of four or more instances of very soft or liquid stools daily or an abdominal pain score of 2 or more OR a CDAI (CD Activity Index) ≥ 220 OR a Harvey-Bradshaw Index \> 8 OR a faecal calprotectin ≥ 250 µg/g And * A endoscopic activity defined by a SES-CD (Simple Endoscopic Score for Crohn Disease) ≥ 6 or a CDEIS (CD Endoscopic Index score) ≥ 7 * Patients with UC presenting inflammatory flare with: A clinical activity defined by a modified Mayo score ≥ 3 OR a Simple Clinical Colitis Activity Index ≥5 OR Patient Reported Outcome (PRO2) ≥ 4 with a subscore of rectal bleeding ≥1 OR a faecal calprotectin ≥ 250 µg/g AND An endoscopic activity defined by a Mayo endoscopic sub-score ≥ 2 Specific for Control cohort: Patient with no colonic lesion(s) visible during the endoscopical examination (neither Crohn's nor other colitis nor cancer) Exclusion Criteria: General criteria: * Commercial Pharmaceutical probiotic administration within the previous month * Treatment with antibiotics (whatever the route of administration) within last 3 months * Non-remission Cancer or in remission for less than 6 months * Any contraindication to colonoscopy and/or biopsy, left to PI discretion * Under guardianship or judiciable protection * Pregnant or breastfeeding women * Currently participating or having participated in the last 3 months to a clinical study with investigational medicine or food supplement Specific for Crohn cohort: * Crohn disease localized only in Ileum * Inflammatory colon pathology other than Crohn's (infectious, drug-induced,…)