The CELESTE cohort will be a three-center prospective cohort associated with the creation of a biobank including Inflammatory Bowel Diseases (IBD) patients with active disease

The CELESTE cohort will be a prospective cohort of IBD patients followed up at Nantes University Hospital, Jules Verne Clinic (Nantes) and/or Confluent Private Hospital (Nantes). The multicentric nature of the cohort including a tertiary referral center and two secondary care centers is a major asset, enabling the enrolment of a broad spectrum of patients, from those naïve to any immunomodulatory treatment to those refractory to multiple biologic therapies.

It will be associated with a multi-omics biobank with the aim of identifying new cellular and molecular signatures of success of the therapeutic strategy at one year.

Inclusion Criteria:

• Patients over 18 years of age;
• Patients with an established diagnosis of IBD: CD, UC, unclassified IBD or refractory chronic pouchitis;
• Patients with active disease requiring surgery or endoscopy, whether performed at diagnosis or prior to initiation of new therapy;
• Patients who have given written consent to participate in the study and to keep biological samples for research purposes

Exclusion Criteria:

• Patients refusing to participate in the cohort;
• Patients with chronic inflammatory bowel disease quiescent at inclusion;
• Patients with a contraindication to general anaesthesia;
• Vulnerable patients (under court protection, curators, guardians);

IBD patients who are immunomodulator-naive or refractory to one or more lines of immunosuppressive, biotherapy, or small molecule therapy