The differential diagnosis of Crohn's disease and ulcerative colitis.

Most cases of inflammatory bowel disease (IBD) can be correctly labelled as Crohn's disease (CD) or ulcerative colitis (UC) with careful initial gross and microscopic examination of biopsy and resection specimens together with close clinical and radiological correlation. Until we understand more of the aetiology and immunology of IBD we should admit that there are limitations imposed by current diagnostic criteria, consider the use of reporting proforma to improve diagnostic accuracy, and accept that in a small number of patients clinicopathological features will overlap, and CD may masquerade as UC.