Laboratory evaluation including novel diagnostic markers of inflammatory bowel disease

Laboratory markers in inflammatory bowel diseases (IBD) may be used for several reasons. Their evaluation may be performed in order to diagnose IBD, to substratify it to ulcerative colitis (UC) or Crohn's disease (CD), and to determine prognosis (including response to therapy). In addition, disease activity needs to be constantly re-evaluated. When using a laboratory marker in IBD one should recognize that no laboratory marker can serve all functions, and that they are adjunct bricks, not sole determinants, in determining diagnosis, prognosis, activity etc. Their importance is usually in being accessible, easy to perform, not invasive, and relatively cheap compared with the endoscopic and imaging studies used for the same tasks. The laboratory markers discussed are the serologic markers frequently used for determining IBD diagnosis and prognosis and the inflammatory indices in serum and feces. The purpose of the review is not to perform an exhaustive description of every laboratory marker studied in IBD, but to mention the ones that the author believes are most relevant currently and for the next 5 years.