TOward a Better Understanding of the autoPhagy Machinery for the Identification of Potential Novel Biomarkers and Therapeutic Targets in Crohn's Disease - TOPIC Study

\--- Inclusion Criteria : For CD patients : * Aged over 18 years * Men or non-pregnant women * Patients with a diagnosis of terminal ileum or ileocolonic CD for at least three months who requires to perform an ileocolonoscopy for routine follow-up * Inactive and moderately to severely active CD according to the Harvey-Bradshaw index * Stable doses of oral prednisone (≤30 mg per day) or budesonide (≤9 mg per day), mesalamine, concomitant immunosuppressive agents, biologics including anti-TNF agents, vedolizumab or ustekinumab are allowed at stable dose for at least three months before inclusion. * Informed written consent * Beneficiary or beneficiary of a social security system For non IBD controls : * Aged over 18 years * Men or non-pregnant women * Patients without a diagnosis of Crohn's disease who requires to perform an ileocolonoscopy for routine follow-up * Informed written consent * Beneficiary or beneficiary of a social security system * Exclusion Criteria \* : For patients and non-IBD controls : * Existing pregnancy, lactation, or intended pregnancy within the next 15 months * History of disease, including mental/emotional disorder that might interfere with their participation in the study * Serious secondary illnesses of an acute or chronic nature, which in the opinion of the investigator renders the patient unsuitable for inclusion into the study * Inability to comply with the protocol requirements * Presence of an ileo-/colonic stoma * Patients with known colonic stricture and exclusive or predominant anal or perineal Crohn's disease lesions * Known previous or concurrent malignancy (other than that considered surgically cured, with no evidence for recurrence for 5 years) * Short bowel syndrome * Concomitant Clostridium difficile superinfection * Indeterminate colitis * Concomitant leukocyte apheresis * Patients who will be exposed to antibiotics 4 weeks prior the inclusion, given the potential impact on the detection of AIEC colonization in ileal biopsies * Patients who denied the protocol, not ability to accept or sign consent of the protocol * Subject involved in another interventional research with an exclusion period still in progress at inclusion * Pregnant women, women in labor or breastfeeding women\*. * Persons deprived of their liberty by a judicial or administrative decision * Persons under psychiatric care * Persons admitted to a health or social institution for purposes other than research * Adults subject to a legal protection measure (guardianship, curatorship) * Subject involved in another clinical trial