Evidence-based

References

Every statement on ibdeim.org is grounded in the published medical literature. Below, the key points are grouped by topic and linked to the peer-reviewed studies that support them. Sources were retrieved from a curated IBD extraintestinal-manifestations research library and verified against the U.S. National Library of Medicine (PubMed). Last verified July 2026.

Extraintestinal manifestations of IBD

Up to 40% of people with IBD develop manifestations outside the gut — in the skin, joints, eyes, bones, blood, and liver.1–3

Skin — erythema nodosum & pyoderma gangrenosum

The skin is the most common site; erythema nodosum tracks the bowel disease while pyoderma gangrenosum runs its own course and must not be debrided.4–6

Joints — enteropathic spondyloarthritis (SpA)

Joint involvement is the most common EIM: a spondyloarthritis with peripheral and axial (ankylosing spondylitis, sacroiliitis) forms.7–9

Eyes — uveitis & episcleritis

Episcleritis is mild and flare-linked; uveitis is deeper and sight-threatening — a same-day emergency.10, 11

Bones — low bone density

Inflammation, steroids, and malabsorption lower bone density, often silently, until a fracture.12

Blood — anemia & venous thromboembolism

IBD commonly causes anemia and roughly triples the risk of blood clots, especially during flares and hospitalisation.13, 14

Liver — primary sclerosing cholangitis

PSC inflames the bile ducts, runs its own course, and raises colorectal- and bile-duct-cancer risk.15, 16

References

  1. Wu H, et al. Extraintestinal Manifestations of Inflammatory Bowel Disease: A Focus on Kidney Complications. Int J Mol Sci. 2026. PMID: 42196598.
  2. Sachdeva K, et al. Advanced therapies for extraintestinal manifestations of IBD: a systematic review and meta-analysis. Inflamm Bowel Dis. 2026. PMID: 42108201.
  3. Colman RJ, et al. Incidence and prevalence of immune-mediated extraintestinal manifestations in pediatric inflammatory bowel disease: a systematic review and meta-analysis. Crohns Colitis 360. 2026. PMID: 42027410.
  4. De Simone C, et al. Psoriasis and erythema nodosum: two comorbidities of inflammatory bowel diseases. G Ital Dermatol Venereol. 2013. PMID: 23588143.
  5. Downey K, et al. Pyoderma Gangrenosum and Inflammatory Bowel Disease: Recent Insights into Epidemiology, Pathogenesis, and Therapeutic Approaches. J Inflamm Res. 2025. PMID: 41255587.
  6. Scocca V, et al. Oral Manifestations in Patients with Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis. Dent J (Basel). 2026. PMID: 42187628.
  7. Végh E, et al. Inflammatory Bowel Disease-Associated Spondyloarthritis. J Clin Med. 2026. PMID: 42355848.
  8. Shofa NM, et al. Adalimumab Therapy for Crohn's Disease and Axial Spondyloarthritis in Latent Tuberculosis: A bibliometric-systematic literature review. Sultan Qaboos Univ Med J. 2026. PMID: 41809609.
  9. Malik F, et al. Sacroiliitis in inflammatory bowel disease. Curr Opin Rheumatol. 2024. PMID: 38687285.
  10. Karti O, et al. Human Herpesvirus 6-Associated Unilateral Panuveitis Mimicking Endogenous Endophthalmitis in a Case with Ulcerative Colitis: Report of a Case and Literature Review. Ocul Immunol Inflamm. 2025. PMID: 40476589.
  11. Kurimura K, et al. Long-term remission of severe refractory scleritis associated with ulcerative colitis after proctocolectomy: a case report and literature review. Clin J Gastroenterol. 2026. PMID: 41396399.
  12. Palatianou ME, et al. Signaling pathways associated with bone loss in inflammatory bowel disease. Ann Gastroenterol. 2023. PMID: 36864939.
  13. Gandhi J, et al. Venous Thromboembolism in Pediatric Inflammatory Bowel Disease: A Scoping Review. J Pediatr Gastroenterol Nutr. 2023. PMID: 37455339.
  14. Toplicanin A, et al. Autoimmune Hemolytic Anemia in Inflammatory Bowel Disease-Report of a Case and Review of the Literature. Life (Basel). 2022. PMID: 36362944.
  15. Ho GJK, et al. Epidemiology of primary sclerosing cholangitis in general and IBD populations: a systematic review and meta-analysis. Hepatol Int. 2026. PMID: 42435161.
  16. Angelico R, et al. Colorectal cancer in ulcerative colitis after liver transplantation for primary sclerosing cholangitis: a systematic review and pooled analysis of oncological outcomes. Discov Oncol. 2024. PMID: 39378005.

Compiled by IBDology. Citations are provided for transparency and education and are not a substitute for advice from your own care team.