- Patients who have received, i)any antibiotic within 2 weeks of the screening visit, ii)systemic corticosteroid therapy within 2 weeks of the screening visit, iii)parenteral nutritional therapy within 2 weeks of the screening visit, iv)enteral elemental or polymeric nutritional therapy or exclusively liquid diet within 2 weeks of the screening visit, v) infliximab within 12 weeks of the screening visit, vi)an initiation of therapy with sulphasalazine or with any 5-ASA preparation within 4 weeks of the screening visit or a change in the dose within 2 weeks of the screening visit (Patients on stable doses of sulphasalazine or of a 5-ASA preparation for at least 2 weeks prior to the screening visit are eligible for entry into the study if the total duration of the therapy is at least 4 weeks prior to screening.), vii)an initiation of azathioprine, 6-MP, or methotrexate within 12 weeks of the screening visit or changes in the dose of azathioprine, of 6-MP, or of methotrexate within 4 weeks of screening visit (Patients receiving azathioprine, 6-MP, or methotrexate for at least 12 weeks and at a stable dose for at least 4 weeks prior to the screening visit are eligible for inclusion.), viii)other therapy not listed above for Crohn's disease within 4 weeks of the screening visit, AND/OR ix)any investigational drug within 12 weeks of the screening visit.