Crohn's disease (CD) is a chronic disease with variable frequency of relapses and multiple possible complications. However, appropriate medical and surgical management may enable patients to have a reasonable quality of life.
Natural history
Typically patients with CD have intermittent exacerbations followed by periods of remission, with 10% to 20% of patients experiencing a prolonged remission after the initial presentation.[111]Farmer RG, Whelan G, Fazio VW. Long-term follow-up of patients with Crohn's disease. Relationship between the clinical pattern and prognosis. Gastroenterology. 1985 Jun;88(6):1818-25.
http://www.ncbi.nlm.nih.gov/pubmed/3922845?tool=bestpractice.com
[275]Moum B, Ekbom A, Vatn MH, et al. Clinical course during the 1st year after diagnosis in ulcerative colitis and Crohn's disease. Results of a large, prospective population-based study in southeastern Norway, 1990-93. Scand J Gastroenterol. 1997 Oct;32(10):1005-12.
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[276]Munkholm P, Langholz E, Davidsen M, et al. Disease activity courses in a regional cohort of Crohn's disease patients. Scand J Gastroenterol. 1995 Jul;30(7):699-706.
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Many patients with CD require surgical treatment for the complications of their disease. The use of immunomodulators and biological therapies reduces the risk of surgery and hospitalisation in patients with CD.[277]Burisch J, Kiudelis G, Kupcinskas L, et al. Natural disease course of Crohn's disease during the first 5 years after diagnosis in a European population-based inception cohort: an Epi-IBD study. Gut. 2019 Mar;68(3):423-33.
http://www.ncbi.nlm.nih.gov/pubmed/29363534?tool=bestpractice.com
Patients with isolated ileocolonic disease are likely to undergo surgery, with some studies reporting up to 90% having surgery by 10 years. Of these people, 50% will never require further surgery.[278]Bernell O, Lapidus A, Hellers G. Risk factors for surgery and recurrence in 907 patients with primary ileocaecal Crohn's disease. Br J Surg. 2000 Dec;87(12):1697-701.
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Up to one third of patients with gastroduodenal CD require gastrojejunostomy bypass for obstruction.[279]Murray JJ, Schoetz DJ Jr, Nugent FW, et al. Surgical management of Crohn's disease involving the duodenum. Am J Surg. 1984 Jan;147(1):58-65.
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Predictors of a relatively severe disease include age <40 years at diagnosis, the presence of perianal disease, and initial requirement for corticosteroids.[280]Beaugerie L, Seksik P, Nion-Larmurier I, et al. Predictors of Crohn's disease. Gastroenterology. 2006 Mar;130(3):650-6.
http://www.ncbi.nlm.nih.gov/pubmed/16530505?tool=bestpractice.com
Mortality
CD is associated with a decrease in life expectancy. The mortality rate of patients with CD increases with the duration of the disease, higher comorbidity score, lower socioeconomic status, and in the 30 days post gastrointestinal surgery. One European population-based cohort study of the natural course of CD (that included 488 patients followed prospectively from time of diagnosis) reported 16 (3%) deaths during follow-up at a median 25 months.[277]Burisch J, Kiudelis G, Kupcinskas L, et al. Natural disease course of Crohn's disease during the first 5 years after diagnosis in a European population-based inception cohort: an Epi-IBD study. Gut. 2019 Mar;68(3):423-33.
http://www.ncbi.nlm.nih.gov/pubmed/29363534?tool=bestpractice.com
Colon cancer is the leading cause of disease-related death, and other causes include non-Hodgkin's lymphoma, digestive diseases, pulmonary embolism, and sepsis.[281]Weterman IT, Biemond I, Peña AS. Mortality and causes of death in Crohn's disease. Review of 50 years' experience in Leiden University Hospital. Gut. 1990 Dec;31(12):1387-90.
https://gut.bmj.com/content/gutjnl/31/12/1387.full.pdf
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[282]Card R, Hubbard R, Logan RF. Mortality in inflammatory bowel disease: a population-based cohort study. Gastroenterology. 2003 Dec;125(6):1583-90.
http://www.ncbi.nlm.nih.gov/pubmed/14724808?tool=bestpractice.com
[283]Jess T, Loftus EV Jr, Harmsen WS, et al. Survival and cause specific mortality in patients with inflammatory bowel disease: a long term outcome study in Olmsted County, Minnesota, 1940-2004. Gut. 2006 Sep;55(9):1248-54.
http://www.ncbi.nlm.nih.gov/pubmed/16423890?tool=bestpractice.com
[284]Bernstein CN, Nugent Z, Targownik LE, et al. Predictors and risks for death in a population-based study of persons with IBD in Manitoba. Gut. 2015 Sep;64(9):1403-11.
http://www.ncbi.nlm.nih.gov/pubmed/25227522?tool=bestpractice.com