A comparison of the structure and function of the terminal ileum in Crohn's disease using radiology, the "Dicopac" Schilling test and [14C] G.C.A. breath test.

Twenty patients with Crohn's disease were studied. Thirteen had radiological evidence of involvement of the terminal ileum. None had significant bacterial overgrowth of the small bowel contents and none had had resection of the terminal ileum. In all patients a [14C] glycocholic acid ([14C] G.C.A.) breath test and a "Dicopac" Schilling test were performed to assess terminal ileal function. The data showed poor correlation between the radiological appearance of the terminal ileum and the results of the functional tests. There was also poor correlation between the results of the [14C] G.C.A. breath test and the "Dicopac" Schilling test. Without terminal ileal histology, any assessment of the extent of Crohn's disease of the terminal ileum and of its effect on terminal ileal function, must include the [14C] G.C.A. breath test as well as radiology and the "Dicopac" Schilling test. The limitations of the [14C] G.C.A. breath test as a test of terminal ileal function in Crohn's disease are discussed.