الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Inflammatory bowel disease (IBD), including Crohn’s disease (CD) and ulcerative colitis (UC), are chronic debilitating diseases that occur in populations around the world is characterized by a tendency for chronic or relapsing immune activation and inflammation within the gastrointestinal tract. Crohn’s disease (CD) and ulcerative colitis (UC) are the two major forms of IBD. These two main forms of IBD share many clinical and epidemiologic characteristics, suggesting that underlying cause may be similar.
Crohn’s disease (CD): Is a condition of chronic relapsing inflammation potentially involving the alimentary tract from mouth to anus, but with a propensity for the distal small bowel and proximal large bowel. Inflammation in Crohn’s disease often is discontinuous along the longitudinal axis of the gut and may involve all layers from mucosa to serosa. Diseased segment usually separated by intervening normal bowel leading to the term “skip areas”.
Ulcerative colitis (UC) is a chronic relapsing and remitting inflammatory disorder of the gastrointestinal tract that affects the large bowel. Unlike CD, where inflammatory process is transmural and may affect any part of alimentary tract, uncomplicated UC is confined to the mucosa and restricted to the large bowel. Disease extent can be broadly divided into distal and more extensive disease. Distal disease refers to colitis confined to the rectum (proctitis) or to the rectum and sigmoid colon (proctosigmoiditis). More extensive disease includes Left sided colitis (up to the splenic flexure), Extensive colitis (up to the hepatic flexure) and Pancolitis (affecting the whole colon).
The initial trigger responsible for the onset of IBD is not yet known. A complex interplay between the immune system, environmental factors, such as stress and diet, enteric infections, and genetic factors play a role in the pathogenesis of IBD. Gut microbiota interacts with both the innate and adaptive immune systems, playing a role in maintenance and disruption of gut immune quiescence. Different bacteria have been implicated in the pathogenesis of IBD including C. difficile.
Clostridium difficile is a gram-