Analysis of disease distribution, activity and complications in the patient with inflammatory bowel disease.

Management strategies in Crohn's disease and ulcerative colitis should be based on up-to-date information on disease distribution, extent, activity and complications. A system of structured analysis is suggested, with separate consideration of destructive ulceration, inflammatory activity and other factors. Direct investigation of gut immunity by using whole gut lavage fluid (WGLF) is a valuable new technique of clinical investigation in IBD and related disorders. Recent studies have shown that the concentrations of plasma-derived proteins in WGLF provide objective measures of disease activity; and that this activity is a separate phenomenon from destructive ulceration and fibrosis. Neutrophils in the lumen can be in- investigated by cytology, or by assay of neutrophil elastase in WGLF. Cytokines and other immuno-regulatory mediators can also be detected. These new techniques can provide a description of intestinal immunity and inflammation, based on a non-invasive test of 2-4 h duration. Work in progress shows that patients who respond clinically to elemental diet treatment have unusually high concentrations of soluble IL2 receptor in WGLF; cytokine profiles may facilitate the selection of patients suitable for other new treatment modalities.