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

Inclusion Criteria: 1. Age ≥18 years. 2. Diagnosis of Crohn's disease established on the basis of overall clinical assessment, including compatible clinical history and standard endoscopic, histologic, and/or radiologic findings, as determined by the treating physician. Histologic confirmation at baseline is not required if endoscopy or biopsy is not feasible or clinically inappropriate because of severe disease, poor nutritional status, or intra-abdominal abscess/sepsis. 3. Active Crohn's disease at baseline, as determined by the treating physician. 4. Willingness to initiate and receive exclusive enteral nutrition (EEN) as the sole induction therapy as part of physician-directed routine care. 5. Presence of malnutrition or nutritional risk and clinical indication for EEN. 6. Patients with intestinal complications, including enteric fistula, intestinal stricture, and/or intra-abdominal abscess, are eligible if considered appropriate for EEN-based management by the treating physician. 7. Ability and willingness to provide written informed consent and to comply with study assessments and follow-up for 12 weeks. Optional clarifying note: In participants without histologic confirmation at baseline, the diagnosis may be further confirmed during follow-up when clinically feasible, including by endoscopic biopsy or surgical pathology. Exclusion Criteria 1. Any absolute contraindication to enteral nutrition, including but not limited to gastrointestinal perforation, uncontrolled gastrointestinal bleeding, severe hemodynamic instability/shock, or other conditions where enteral feeding is not clinically appropriate. 2. Immediate need for emergency surgery at baseline. 3. Inability or unwillingness to receive EEN as the sole induction therapy at baseline. 4. Any condition that, in the investigator's opinion, would make participation unsafe or would substantially interfere with study assessments or follow-up.