Crohn's disease is a chronic condition of the gastrointestinal tract. It is characterised by transmural, granulomatous inflammation that occurs in a discontinuous pattern, with a tendency to form fistulae. The cause is unknown but may depend on interactions between genetic predisposition, environmental triggers, and mucosal immunity.
Methods and outcomes
We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of medical treatments to induce remission in adults with Crohn's disease? What are the effects of surgical interventions to induce and maintain remission in adults with small-bowel Crohn's disease? What are the effects of surgical interventions to induce remission in adults with colonic Crohn's disease? What are the effects of medical interventions to maintain remission in adults with Crohn's disease; and to maintain remission following surgery? What are the effects of lifestyle interventions to maintain remission in adults with Crohn's disease? We searched: Medline, Embase, The Cochrane Library, and other important databases up to December 2009 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).
We found 93 systematic reviews, RCTs, or observational studies that met our inclusion criteria.
In this systematic review we present information relating to the effectiveness and safety of the following interventions: aminosalicylates, antibiotics, azathioprine/mercaptopurine, ciclosporin, corticosteroids (oral), enteral nutrition, fish oil, infliximab, methotrexate, probiotics, resection, segmental colectomy, smoking cessation, and strictureplasty.
Crohn's disease is a chronic condition of the gastrointestinal tract.
It is characterised by transmural, granulomatous inflammation that occurs in a discontinuous pattern, with a tendency to form fistulae.The cause is unknown but may depend on interactions between genetic predisposition, environmental triggers, and mucosal immunity.
First-line treatment to induce remission of acute disease is corticosteroids.
Budesonide is generally recommended in mild to moderate ileocaecal disease because it is only slightly less effective in inducing remission than prednisolone and has a superior adverse-effect profile.Prednisolone or methylprednisolone are generally recommended for severe or more extensive disease because of their superior efficacy.
Azathioprine and mercaptopurine are effective in inducing remission and healing fistulae in Crohn's disease, provided that at least 17 weeks of treatment are given. Monitoring for myelosuppression is obligatory.
Aminosalicylates (mesalazine, sulfasalazine) may reduce disease activity, but we don't know which regimen is best to induce remission.
Methotrexate 25 mg weekly increases remission rates and has a corticosteroid-sparing effect. There is consensus that it is also effective for maintenance.Infliximab (a cytokine inhibitor) is effective in inducing and maintaining remission in Crohn's disease, but the long-term adverse-effect profile is unclear; infliximab is therefore generally reserved for treatment of disease that is refractory to treatment with corticosteroids or other immunomodulators.
Antibiotics and ciclosporin are unlikely to be beneficial in inducing remission.
Bowel-sparing surgery to induce remission may be preferable to extensive resection, to avoid short-bowel syndrome. Segmental and sub-total colectomy have similar remission rates.
Laparoscopic resection may reduce postoperative hospital stay, but we don't know whether strictureplasty is effective.
Azathioprine has been shown to be beneficial in maintaining remission in Crohn's disease, either alone or after surgery, and has a corticosteroid-sparing effect, but it is associated with important adverse effects.
Ciclosporin, or oral corticosteroids, alone are unlikely to be beneficial in maintaining remission after medical treatment.
Methotrexate and infliximab may also maintain remission compared with placebo.
Smoking cessation reduces the risk of relapse, and enteral nutrition may be effective.
Fish oil and probiotics have not been shown to be effective.
Mesalazine seems effective in maintaining medically induced remission, but we don't know how effective other aminosalicylates are in maintaining remission.