Inflammatory bowel diseases activity in patients undergoing pelvic radiation therapy

Inflammatory bowel diseases (IBD), which include Crohn’s disease (CD) and ulcerative colitis (UC), are chronic diseases that generally begin in young adulthood and last throughout life. In the western countries, the incidence and prevalence of IBD has increased in the past 50 years, from 6–15/100,000 to 50–200/100,000 persons/year for CD, and from 8–14/100,000 to 120–200/100,000 persons/year for UC (1). Both CD and UC are complex IBD that result from a combination of genetic predispositions and environmental factors including microbiome in the digestive tract (2,3). Specifically, CD is a transmural inflammatory disease which can affect the entire digestive tract, from the mouth to the anus, and may be complicated by abscesses, fistulas or strictures, whereas UC is limited to the mucosa and can affect only the rectum and colon