Inflammatory bowel disease (IBD) refers to two diseases, ulcerative colitis (UC) and Crohn’s disease. Both diseases produce inflammation of the large or small intestines, resulting in diarrhea and abdominal pain.
Inflammation results from a cell-mediated immune response in the gastrointestinal mucosa. The precise etiology is unknown, but evidence suggests that the normal intestinal flora trigger an immune reaction in patients with a multifactorial genetic predisposition, perhaps involving abnormal epithelial barriers and mucosal immune defenses.
The diagnoses of both ulcerative colitis and Crohn’s disease are based on clinical features, the results of barium X-rays, colonoscopy, mucosal biopsy histology, and in some cases operative findings and resected bowel pathology and histology. Recently, patients with IBD have been shown to have antibodies in serum that help distinguish between Crohn’s disease and ulceratice colitis.
In ulcerative colitis patients so called pANCA can often be detectected. Patients suffering from Crohn’s disease often have ASCA of the IgA and/or IgG isotypes, which react with cell wall mannan of a certain strain of Saccharomyces cerevisiae.
In case of IBD, no specific environmental, dietary, or infectious causes have been identified. The immune reaction involves the release of inflammatory mediators, including cytokine and interleukin effects, and TNF.