Inflammatory bowel disease

Inflammatory bowel disease (IBD) is a group of inflammatory conditions of the colon and small intestine. Crohn's disease and ulcerative colitis are the principal types of inflammatory bowel disease. Crohn's disease affects the small intestine and large intestine, as well as the mouth, esophagus, stomach and the anus, whereas ulcerative colitis primarily affects the colon and the rectum. Inflammatory bowel disease (IBD) is a group of inflammatory conditions of the colon and small intestine. Crohn's disease and ulcerative colitis are the principal types of inflammatory bowel disease. Crohn's disease affects the small intestine and large intestine, as well as the mouth, esophagus, stomach and the anus, whereas ulcerative colitis primarily affects the colon and the rectum. In spite of Crohn's and UC being very different diseases, both may present with any of the following symptoms: abdominal pain, diarrhea, rectal bleeding, severe internal cramps/muscle spasms in the region of the pelvis and weight loss. Anemia is the most prevalent extraintestinal complication of inflammatory bowel disease. Associated complaints or diseases include arthritis, pyoderma gangrenosum, primary sclerosing cholangitis, and non-thyroidal illness syndrome (NTIS). Associations with deep vein thrombosis (DVT) and bronchiolitis obliterans organizing pneumonia (BOOP) have also been reported. Diagnosis is generally by assessment of inflammatory markers in stool followed by colonoscopy with biopsy of pathological lesions. IBD is a complex disease which arises as a result of the interaction of environmental and genetic factors leading to immunological responses and inflammation in the intestine. Dietary patterns are associated with a risk for ulcerative colitis. In particular, subjects who were in the highest tertile of the healthy dietary pattern had a 79% lower risk of ulcerative colitis. Gluten sensitivity is common in IBD and associated with having flareups. Gluten sensitivity was reported in 23.6 and 27.3% of Crohn's disease and ulcerative colitis patients, respectively. A diet high in protein, particularly animal protein, may be associated with increased risk of inflammatory bowel disease and relapses. As a result of microbial symbiosis and immunity, alterations in the gut microbiome may contribute to inflammatory gut diseases. IBD-affected individuals have been found to have 30–50 percent reduced biodiversity of commensal bacteria, such as decreases in Firmicutes (namely Lachnospiraceae) and Bacteroidetes. Further evidence of the role of gut flora in the cause of inflammatory bowel disease is that IBD-affected individuals are more likely to have been prescribed antibiotics in the 2–5 year period before their diagnosis than unaffected individuals. The enteral bacteria can be altered by environmental factors, such as concentrated milk fats (a common ingredient of processed foods and confectionery) or oral medications such as antibiotics and oral iron preparations. Loss of integrity of the intestinal epithelium plays a key pathogenic role in IBD. Dysfunction of the innate immune system as a result of abnormal signaling through immune receptors called toll-like receptors (TLRs)—which activates an immune response to molecules that are broadly shared by multiple pathogens—contributes to acute and chronic inflammatory processes in IBD colitis and associated cancer.Changes in the composition of the intestinal microbiota are an important environmental factor in the development of IBD. Detrimental changes in the intestinal microbiota induce an inappropriate (uncontrolled) immune response that results in damage to the intestinal epithelium. Breaches in this critical barrier (the intestinal epithelium) allow further infiltration of microbiota that, in turn, elicit further immune responses. IBD is a multifactorial disease that is nonetheless driven in part by an exaggerated immune response to gut microbiota that causes defects in epithelial barrier function.