Laboratory evaluation of inflammatory bowel disease

Although a thorough clinical history and physical exam may raise suspicion of Crohn disease (CD) or ulcerative colitis (UC), a focused laboratory evaluation can facilitate further differentiation between inflammatory bowel disease (IBD) and noninflammatory bowel disease - in particular, distinguishing between IBD, infectious processes, and functional bowel disorders. These blood and stool studies, in combination with clinical presentation, can help determine which child may require more extensive or invasive testing, such as radiological and endoscopic evaluation to definitively diagnose IBD. Not only can a carefully chosen laboratory assessment help determine which child may require more invasive testing, but they provide important information about inflammation and function of other organ systems involved. Additionally, some of these tests may provide insight into disease course (IBD serologies), be used for objective monitoring of disease activity (C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and fecal calprotectin), and are possible surrogates for mucosal healing (fecal calprotectin), which facilitates the ability for the clinician to employ more precise targeted therapies to optimize care.