text: <unk>  is inflammation and damage to the lower parts of the colon after exposure to x-rays or other ionizing<unk>  as a part of<unk>  therapy.<unk>  most commonly occurs after treatment for cancers such as cervical cancer, prostate cancer, and colon cancer.<unk>  involves the lower intestine, primarily the sigmoid colon and the rectum.The rectum is at risk of injury during pelvic irradiation because of its fixed position and close proximity to target organs. In 1897, Walsh was the first to discover the association between X-ray<unk>  and the damaging effect on GIT tract in a person working with the<unk>  energy.He further reported the improvement in the symptoms if exposure being shielded by the lead. In 1942, the early and late intestinal effect of radiotherapy was first described by Warren and Friedman. Based on the duration of symptoms,<unk>  may be classified as either acute or chronic. The exact pathogenesis of<unk>  is not fully understood however it is thought that acute<unk>  is due to direct damage of the lining (epithelium) of the colon.Chronic<unk>  occurs in part because of damage to the blood vessels which supply the colon and results in full-thickness ischemia and fibrotic changes and ultimately the colon is therefore deprived of oxygen and necessary nutrients.<unk>  must be differentiated from infectious colitis, inflammatory bowel disease, ischemic colitis, medication-associated colitis, chemical colitis, and allergic colitis. The reported incidence of any transient acute<unk>  is thought to range from 50% to 100%. The incidence of chronic<unk>  is estimated to be 2000-20,000 in every 100,000<unk> s. Common complications of<unk>  include intestinal obstruction due to stricture, fecal incontinence due to overflow and fistula formation due to concomitant injury to nearby organs. The laboratory findings in a patient with acute<unk>  can be within reference range however, in case of chronic injury anemia, elevated white blood cell, deranged LFTs and electrolyte abnormalities can be seen.
option_0: Radiation proctitis
option_1: Chronic bacterial prostatitis
option_2: Cervicitis
option_3: Prostatitis
option_4: Pelvic inflammatory disease
option_5: Benign prostatic hyperplasia
option_6: Radiation colitis
option_7: Rectal prolapse