Exclusive Enteral Nutrition Therapy for Active and Complicated Crohn's Disease

The goal of this observational study is to evaluate the effectiveness and safety of exclusive enteral nutrition (EEN) in adults with active Crohn's disease (CD), particularly in patients with complicated disease such as stricturing disease, enteric fistula, and intra-abdominal abscess. The main questions it aims to answer are: * What is the clinical remission rate at Week 12 in adults with active CD treated with EEN? * How does EEN affect clinical response, endoscopic outcomes, inflammatory markers, nutritional status, BMI, and safety during follow-up? Participants will: * start EEN at baseline and be followed through Week 12; * receive EEN as the main treatment approach during the study period; * complete clinical, laboratory, nutritional, and safety assessments at prespecified follow-up visits; * undergo endoscopic assessment when endoscopy is performed as part of routine care; and * if clinically indicated, some participants with large intra-abdominal abscesses may receive percutaneous drainage and necessary antibiotic treatment.