Crohn's disease is a chronic inflammatory disease that mainly affects the gastrointestinal tract. The disease may be progressive in some people, and a proportion may develop extra‑intestinal manifestations. Crohn's & Colitis UK estimate there are at least 115,000 people in the UK with Crohn's disease. The causes of Crohn's disease are widely debated. Smoking and genetic predisposition are 2 important factors that are likely to play a role.
Typically people with Crohn's disease have recurrent relapses, with acute exacerbations interspersed with periods of remission or less active disease. Whether a relapse refers to a recurrence of symptoms or the appearance of mucosal abnormalities before the development of symptoms remains the subject of dispute. Treatment is largely directed at symptom relief rather than cure, and active treatment of acute disease (inducing remission) should be distinguished from preventing relapse (maintaining remission).
Management options for Crohn's disease include drug therapy, attention to nutrition, smoking cessation and, in severe or chronic active disease, surgery.
The aims of drug treatment are to reduce symptoms, promote mucosal healing, and maintain or improve quality of life, while minimising toxicity related to drugs over both the short‑ and long‑term. Glucocorticosteroid treatment, aminosalicylate treatment, antibiotics, immunosuppressants and tumour necrosis factor (TNF)‑alpha inhibitors are currently considered to be options for treating Crohn's disease. Enteral nutrition has also been used widely as first‑line therapy in children and young people to facilitate growth and development, but its use in adults is less common. Between 50 and 80% of people with Crohn's disease will eventually need surgery for strictures causing symptoms of obstruction, other complications such as fistula formation, perforation or failure of medical therapy.
The 2015 routine surveillance review of the guideline highlighted evidence on the combined use of TNF‑alpha inhibitor and immunosuppressant medications for inducing remission in people with severe active Crohn's disease. The recommendations were updated in May 2016, to provide guidance on the combined use of TNF‑alpha inhibitor biologics (infliximab or adalimumab) together with an immunosuppressant medication, compared with biologic medication given alone. An update in May 2019 made new recommendations on maintaining remission after surgery.