Improvement and standardization of the conservative therapy of inflammatory bowel disease has lead to a better prognosis for the patients. During the acute flare of Crohn's disease steroids are still the standard therapy, whereas 5-aminosalicylic acid (5-ASA) preparations are used for maintenance therapy during remission. In contrast ulcerative colitis may be treated with 5-ASA also for acute exacerbations. The development of new drugs as for example the topical steroids helps to improve life quality of the patients by reducing adverse side effects. Potent immunosuppressants as azathioprine and methotrexate are useful in chronic active and refractory disease. Cyclosporin A plays a role in severe steroid refractory colitis. In the future immunomodulation by application of antiinflammatory cytokines or antibodies to inflammatory cytokines may have its place in the treatment of IBD patients. In some cases, however, the conservative therapy reaches its limits. Mistakes in the therapy are made, when these limits are not recognized and complications are not discovered in time.