Proposed classification of patient subgroups in Crohn's disease

Clinical studies of Crohn's disease must rely upon homogeneity of patient subgroups. We do not believe that merely 'lumping' all cases into the Procrustean bed of a numerical index accomplishes this purpose. We therefore propose that all cases be described primarily by anatomical location (e.g. gastroduodenitis, jejunitis, ileitis, colitis, perianal disease, etc.) and anatomical extent (localised or diffuse), with modifiers for disease behaviour (primarily fibrostenotic, primarily inflammatory, or primarily fistulising) and operative history (primary or recurrent).