Review article: the role of non-biological drugs in refractory inflammatory bowel disease.Ng SC, Chan FK, Sung JJ. Aliment Pharmacol Ther. 2010 Dec 8. [Epub ahead of print] Background Up to one-third of patients with inflammatory bowel disease (IBD) do not respond to, or are intolerant of conventional immunosuppressive drugs. Although biological agents are alternative treatments, they may not be suitable or available to some patients. Aim To review the evidence for use of nonbiological drugs in the treatment of patients with IBD refractory to corticosteroids or thiopurines. Methods A literature search was performed using PubMed for English language publications with predetermined search criteria to identify relevant studies. Results Published evidence from uncontrolled series and controlled clinical trials has been used to produce a practical approach relevant to clinical practice which incorporates the indication, optimal dose, and side effects of various therapies including tacrolimus, methotrexate, thalidomide, tioguanine, mycophenolate mofotil, leucocyte apheresis, nutritional therapy, antibiotics, probiotics, allopurinol, rectal acetarsol and ciclosporin in the treatment of patients with refractory ulcerative colitis and Crohn’s disease. Approaches to optimise thiopurine efficacy are also discussed. Conclusions Patients with IBD refractory to corticosteroids or thiopurines may respond to alternative anti-inflammatory chemical molecules, but the evidence base for many of these alternatives is limited and further trials are needed.