Diagnostic markers of inflammatory bowel disease.

The diagnosis of inflammatory bowel disease is usually straightforward, based on a detailed history and physical examination, along with standard radiographic and endoscopic investigations, biopsies, and laboratory parameters. More challenging is the search for clinically useful, noninvasive markers for Crohn disease and ulcerative colitis to accurately screen cases with nonspecific and indolent symptoms. Equally required are diagnostic markers that discriminate between these two disorders in cases with indeterminate colitis. Another dilemma for clinicians is that there are no simple measures to observe disease activity and predict relapses. This review describes the recent advances in diagnostic markers that afford the ability to screen for inflammatory bowel disease, discriminate between its types, and monitor disease activity. These include serological, fecal, and tissue markers; permeability tests; and diagnostic imaging using color Doppler ultrasonography.