Precision Crohn's Disease Management Utilizing Predictive Protein Panels (ENvISION)

Phase I - Cross-sectional Study (CD and Suspected IBD) Inclusion Criteria: 1. Age criteria: \> 1 year to \< 22 years of age 2. Diagnosis of Crohn's disease, anti-TNF naïve, and colonoscopy scheduled OR 3. Clinical suspicion for IBD (treatment naïve) and colonoscopy scheduled 4. Permission of parent/guardian and assent or consent of research participant Exclusion Criteria: 1. Any prior treatment with an anti-TNF, such as infliximab, adalimumab, certolizumab or golimumab 2. Known diagnosis of ulcerative colitis (UC) or inflammatory bowel disease-unspecified (IBD-U) 3. Active or prior evidence of internal (abdominal/pelvic) penetrating fistula(e) 4. Active intra-abdominal abscess or perianal abscess 5. Active Clostridium difficile infection or other known enteric infection in last 2 weeks 6. Current ileostomy or colostomy, extensive small bowel resection, ileoanal pouch or short bowel syndrome 7. History of autoimmune disease (including autoimmune hepatitis, primary sclerosing cholangitis, thyroiditis, psoriasis or juvenile idiopathic arthritis) 8. Any condition that in the opinion of the PI will prevent the research participant from taking part in this study Phase I - Cross-sectional Study (healthy volunteers) Inclusion Criteria: 1. Age criteria: \> 1 year to \< 22 years of age 2. Any CCHMC patient 3. Permission of parent/guardian and assent or consent of research participant Exclusion Criteria: 1. Known diagnosis of one or more of the following: irritable bowel syndrome, gastroesophageal reflux, constipation, BMI\>95% for age, small intestinal bacterial overgrowth (SIBO) or history of intestinal polyps 2. Received any antibiotic in the last 30 days or known viral or bacterial illness in the last 30 days 3. Any NSAID use in the last 14 days 4. History of an autoimmune disease (including diabetes, autoimmune hepatitis, primary sclerosing cholangitis, thyroiditis, psoriasis or juvenile idiopathic arthritis) 5. Any condition that in the opinion of the PI will prevent the research participant from taking part in this study Phase II - Longitudinal Study of Participants with CD Inclusion Criteria: 1. Age criteria: \> 1 year to \< 22 years of age 2. Diagnosis of Crohn's disease with: 1. Luminal inflammation (ulcerations in ileum and/or colon visible by ileocolonoscopy) and 2. Endoscopic evidence of active Crohn's disease (up to 90 days prior to starting anti-TNF) OR if no colonoscopy within 90 days then fecal calprotectin ≥250 µg/g or fecal lactoferrin \>10 µg/g (\<90 days from starting anti-TNF) 3. Anti-TNF naïve 4. Starting infliximab or adalimumab (or either biosimilar) 5. Permission of parent/guardian and assent or consent of research participant Exclusion Criteria: 1. Crohn's disease limited to esophagus, stomach, duodenum or jejunum 2. Prior treatment with infliximab, adalimumab, certolizumab or golimumab 3. Known diagnosis of Ulcerative colitis (UC) or inflammatory bowel disease-unspecified (IBD-U) 4. Active or prior evidence of internal (abdominal/pelvic) penetrating fistula(e) 5. Active intra-abdominal abscess or perianal abscess 6. Active Clostridium difficile infection or other known enteric infection in last 2 weeks 7. Current ileostomy or colostomy, extensive small bowel resection, ileoanal pouch or short bowel syndrome 8. History of autoimmune disease (including autoimmune hepatitis, primary sclerosing cholangitis, thyroiditis, psoriasis or juvenile idiopathic arthritis) 9. Contraindications to MRI scanning, such as metal implants/non-compatible medical devices or medical conditions 10. Any condition that in the opinion of the PI will prevent the research participant from taking part in this study