Use of Crohn's Disease Exclusion Diet on Top of Standard Therapy Versus Standard Therapy Alone in Unstable Pediatric Crohn's Disease Patients.

Inclusion Criteria: * Child/Adolescent aged 6-17 years with a confirmed diagnosis of CD (for at least 3 months) with an active disease (defined as: wPCDAI \>12.5 or CRP \> 2 times upper limit or calprotectin levels \>250µg/g if available) despite anti-inflammatory (5-ASA and derivates), corticosteroids, immunomodulator (thiopurines or methotrexate) and/or biologic therapy (anti-TNF, anti-integrin anti-IL23 antibodies) * For girls of childbearing age: a negative pregnancy test, and use of an effective method of contraception (abstinence, oral contraceptives, intra-uterine device, diaphragm with spermicide and condom) * Patient willing to comply with daily intake of an exclusion diet * Informed and signed consent of parents * Patient affiliated to social security (or health insurance) Exclusion Criteria: * Active perianal fistulizing disease * Internal fistula or evidence of un-drained and un-controlled abscess/phlegmon * Patient who require CD-related surgical therapy * Patient with known allergy to cow milk's proteins * Patient incapable to follow CDED for a prolonged period * Pregnancy, breastfeeding * Patient already included in an interventional study