Colo-rectal biopsy in inflammatory bowel disease

The term inflammatory bowel disease (IBD) is viewed as all-inclusive, covering the full panoply of intestinal disorders in which inflammatory changes are a prominent feature, including those of infectious, toxic, and intrinsic origin as well as the idiopathic entities ulcerative colitis and Crohn's disease. This chapter describes and discusses those aspects of colo-rectal biopsy in IBD which can help pathologists make optimal interpretations. The areas covered are: 1) methods used to prepare biopsy specimens for study, 2) normal histologic findings and common artefacts, 3) basic pathologic changes occurring in IBD, 4) a general approach to differential diagnosis in IBD, and 5) discussion of the various individual forms of IBD. The importance of full and reliable information exchange between the endoscopist and pathologist is stressed. Special attention is given to features in biopsy specimens which help in differentiating between ulcerative colitis and Crohn's disease. Other entities discussed are bacterial dysenteries; gonococcal proctitis; tuberculosis; Whipple's disease; amebiasis; balantidiasis; schistosomiasis; cryptosporidiosis; lymphopathia venereum; cytomegalovirus infection; histoplasmosis; antibiotic colitis; IBD due to cytotoxic drugs (5-FU), heavy metals, and foodstuffs; irradiation colitis; ischemic colitis; solitary ulcer syndrome; diverticulitis; and colitis secondary to obstruction. The term pseudomembranous enterocolitis is also considered.