Laboratory evaluation of pediatric inflammatory bowel disease

In the preceding paragraphs, we attempted to provide an overview of the laboratory tests available that can be used in the initial work up of the child with suspected inflammatory bowel disease. Although a thorough clinical history and physical exam can raise suspicion of CD or UC it is important to include a focused laboratory evaluation. A combination of blood and stool tests (markers of inflammation i.e., fecal calprotectin, fecal lactoferrin or of infectious etiologies i.e. stool cultures) may further differentiate between IBD and non-IBD-in particular, infectious processes and functional bowel disorders. Not only can a carefully chosen combination of blood and stool studies help determine which child may require more invasive testing, but they can also be used in the initial phenotyping of the disease i.e., CD versus UC. Moreover, there are laboratory tests available, specifically IBD serologic markers such as ASCA and anti-CBir1, which can be employed to subtype CD and potentially provide the clinician with the ability to prognosticate disease severity. The definitive diagnosis of IBD is made by combining historical features, physical examination, radiological findings and endoscopy and biopsy. However, laboratory investigations provide important information about inflammation and function of other organ systems that may or may not be involved with the child with IBD, which ultimately helps guide the clinician toward more invasive testing.