The diagnosis of IBD requires a multidisciplinary approach involving a team of specialists that includes gastroenterologists, nurses, radiologists, and pathologists. The histologic examination of endoscopic biopsies or resection specimens is a crucial element in the diagnostic workup of a patient with suspected IBD and assists in making a final diagnosis, differentiating between UC and CD and other forms of colitis, and in the diagnosis of complications. An adequate number of biopsies and careful handling of the tissue are essential for an accurate diagnosis.