• Crohn's disease;
  • extraintestinal complications;
  • natural history;
  • osteoporosis;
  • thromboembolism;
  • demyelinating disorders;
  • colorectal dysplasia;
  • colorectal cancer;
  • small intestinal cancer;
  • mortality;
  • population-based



Crohn's disease (CD) is a chronic, progressive, destructive disease. Numerous intestinal and extraintestinal complications and manifestations can occur during its clinical course. This literature review summarizes our current knowledge of the long-term complications, extraintestinal complications, and mortality in CD in adults as reported in population-based studies that include long-term follow-up results.


A literature search of English and non-English language publications listed in the electronic databases of Medline (source PubMed, 1935 to July, 2009).


The relative risk of incident fractures is increased in CD patients by ≈30%–40%. These patients have also have a 3-fold increased risk of deep venous thrombosis and pulmonary embolism. A variety of extraintestinal manifestations (primary sclerosing cholangitis, ankylosing spondylitis, iritis/uveitis, pyoderma gangrenosum, erythema nodosum) and diseases (asthma, bronchitis, pericarditis, psoriasis, rheumatoid arthritis, and multiple sclerosis) are associated with CD. The risks of colorectal and small bowel cancers relative to the general population are 1.4–1.9 and 21.1–27.1, respectively. A slightly increased risk of lymphoma, irrespective of medication use, has been reported in a recent meta-analysis of population-based studies. Overall mortality is slightly increased in CD, with a standardized mortality ratio of 1.4.


CD is frequently associated with disease complications and extraintestinal conditions. Whether the impact of changing treatment paradigms with increased use of immunosuppressives and biologic agents can reduce disease complications and associated conditions is unknown. (Inflamm Bowel Dis 2011;)