This prospective study aims to provide real-world evidence of the effectiveness of the NEP + CDED diet in paediatric patients with Crohn's disease under conditions of routine clinical practice.

Pediatric Crohn's disease is a chronic inflammatory disorder of the gastrointestinal tract that impacts growth and quality of life. Exclusive enteral nutrition (EEN) is the standard dietary treatment to induce remission, although its use is limited by low acceptability and strict dietary restrictions.

The combination of partial enteral nutrition (PEN) with the Crohn's Disease Exclusion Diet (CDED) represents a more tolerable alternative that reduces exposure to harmful dietary components and has shown efficacy in inducing clinical remission in previous studies.

This observational, prospective, multicenter study will evaluate the effectiveness of CDED+PEN in routine clinical practice in pediatric patients (8-18 years) with active Crohn's disease. The primary objective is to assess the proportion of patients achieving clinical remission (wPCDAI ≤ 12.5) and mucosal healing (MINI Index < 8), steroid-free at weeks 6, 12, and 24, and anti-TNF-free at week 24.

Secondary objectives include assessing health-related quality of life (IMPACT-III), treatment satisfaction and gastrointestinal tolerance, treatment persistence, and estimation of healthcare resource utilization and associated costs. The study is observational, descriptive, and non-interventional with respect to drugs, and will be conducted in pediatric patients initiating CDED+PEN as part of standard clinical care. Treatment prescription will be independent of study participation, and patients who receive the indication may be invited to participate after providing informed consent together with their parents or legal guardians.

Primary outcome measures include the frequency of patients in steroid-free clinical remission at weeks 6, 12, and 24, anti-TNF-free remission at week 24, and the proportion achieving mucosal healing (MINI Index < 8) at the same time points. Secondary analyses will include quality of life scores (IMPACT-III), distribution of questionnaire responses on satisfaction and tolerance, treatment persistence assessed by survival analysis, and cost estimates based on healthcare resource use.

This study will provide real-world evidence on the effectiveness, acceptability, and sustainability of the dietary approach with CDED+PEN in pediatric Crohn's disease under routine clinical practice conditions.

Inclusion Criteria:

• Patients with Crohn's disease (diagnosis based on clinical, laboratory, endoscopic, radiological, and histological criteria, according to the revised Porto criteria of the ESPGHAN for the diagnosis of inflammatory bowel disease in children and adolescents);
• Aged between 8 and 18 years;
• Who are about to start treatment with NEP + CDED, i.e. CDED-naive patients who may have previously received treatment with NEE;
• With active Crohn's disease defined by the Weighted Paediatric Crohn's Disease Activity Index (wPCDAI) ≥ 12.5;
• With data collection available for the following 6 months;
• Able to follow the study protocol or whose parent/caregiver is able to adhere to the study protocol, according to the investigator's perspective.

Exclusion Criteria:

• Patients with ulcerative colitis and/or unclassified inflammatory bowel disease.
• Patients with more than 36 months of disease progression.
• Penetrating (B3) and/or non-inflammatory stenosing (B2) pattern.
• Active perianal disease.
• Presence of extraintestinal manifestations.
• Patients who, in the investigator's opinion, will require surgical treatment or initiation of steroids or biological drugs (anti-TNF, vedolizumab or ustekinumab) within the next 3 months and for whom nutritional support is indicated exclusively as a bridge. Patients who are undergoing biological treatment but discontinue treatment due to non-response and initiate CDED+NEP are not excluded.

Patients aged 8-18 years with Crohn's disease initiating treatment with exclusive enteral nutrition (EEN) plus the Crohn's Disease Exclusion Diet (CDED) and whose wPCDAI value is equal to or greater than 12.5.