The incidence of IBD is rapidly increasing in newly industrialized countries strongly implicating environmental factors. The pathogenesis of IBD is not fully understood, but key influences are thought to include genetics, environmental factors, immune response, and gut microbiota.It is recognised that the availability of vitamin D is important in regulating gut mucosal immunity; with studies suggesting that vitamin D may affect gut epithelial integrity, innate immune barrier function, and the development and function of T cells The predominant symptoms of IBD are diarrhea, abdominal pain, gastrointestinal bleeding, weight loss, malnutrition and fatigue which can substantially impact a patient's quality of life (QoL), largely due to the psychosocial impact of symptoms. A survey of IBD outpatients found that concerns about loss of bowel control, producing unpleasant odours, achieving their full potential in the workplace, feeling dirty or smelly, and issues with sexual relationships, ranked highly for both UC and CD
Inflammatory bowel disease (IBD) is characterised by chronic, relapsing inflammation of the intestinal mucosa and an inability to down regulate the inflammatory immune response once activated. IBD encompasses ulcerative colitis (UC), Crohn's disease (CD) and indeterminate colitis which is not clearly diagnosed as UC or CD. The peak age of onset of IBD is 15 to 30 years, with a second smaller peak occurring between 50 and 70 years of age