For clinicians

Provider Resources

Crohnz.org is written for patients. This page is the clinician-facing companion — a concise, evidence-anchored primer on intestinal Crohn's disease for trainees and non-specialist providers. Every reference below has been verified against PubMed and links to its record. For the surgical evidence base, see Crohnsology.org; for perianal disease, see Pcrohns.org.

Disease behaviour & natural history

Crohn's phenotype is not static: inflammatory disease progresses to stricturing or penetrating behaviour in a substantial fraction of patients over time, which reframes early treatment decisions.

  1. Louis E, Collard A, Oger AF, et al. Behaviour of Crohn's disease according to the Vienna classification: changing pattern over the course of the disease. Gut. 2001;49(6):777-82. PMID 11709511

Medical therapy & treat-to-target

Combination immunosuppression outperforms monotherapy in appropriate candidates, and the field has moved from symptom control to objective targets (endoscopic/mucosal healing).

  1. Colombel JF, Sandborn WJ, Reinisch W, et al. Infliximab, azathioprine, or combination therapy for Crohn's disease (SONIC). N Engl J Med. 2010;362(15):1383-95. PMID 20393175
  2. Turner D, Ricciuto A, Lewis A, et al. STRIDE-II: an update on the Selecting Therapeutic Targets in IBD initiative — determining therapeutic goals for treat-to-target strategies. Gastroenterology. 2021;160(5):1570-83. PMID 33359090

Post-operative recurrence

Endoscopic recurrence predicts clinical relapse after ileocolic resection; risk-stratified prophylaxis with early colonoscopy-guided step-up reduces recurrence.

  1. Rutgeerts P, Geboes K, Vantrappen G, et al. Predictability of the postoperative course of Crohn's disease. Gastroenterology. 1990;99(4):956-63. PMID 2394349
  2. De Cruz P, Kamm MA, Hamilton AL, et al. Crohn's disease management after intestinal resection: a randomised trial (POCER). Lancet. 2015;385(9976):1406-17. PMID 25542620

Modifiable risk & paediatric care

Tobacco smoking measurably worsens the natural history of Crohn's disease; in children, exclusive enteral nutrition is a first-line option for inducing remission.

  1. To N, Gracie DJ, Ford AC. Systematic review with meta-analysis: the adverse effects of tobacco smoking on the natural history of Crohn's disease. Aliment Pharmacol Ther. 2016;43(5):549-61. PMID 26749371
  2. van Rheenen PF, Aloi M, Assa A, et al. The medical management of paediatric Crohn's disease: an ECCO-ESPGHAN guideline update. J Crohns Colitis. 2021;15(2):171-94. PMID 33026087

When to operate, and bowel-sparing surgical strategy, are covered on Crohnsology.org (surgical evidence hub). This digest is educational and does not replace clinical judgement or society guidelines.