Radiation proctitis is a term describing rectal injury after pelvic radiation therapy. Based on the onset of symptoms, radiation proctitis can be acute or chronic, with a slightly different mechanism of injury and symptoms. A detailed patient history revealing prior pelvic radiation in the setting of lower gastrointestinal tract symptoms are highly suggestive of radiation proctitis. The diagnosis is made with invasive methods, such as colonoscopy and rectosigmoidoscopy.
Radiotherapy is still one of the most widely used treatment modalities for malignant diseases of the pelvis (including gynecological, gastrointestinal, and genitourinary). Approximately 5-20% of patients suffer from some form of rectal injury as a result of the therapy and it is known as radiation proctitis   . Depending on the onset of symptoms and the mechanism of injury, two main types are described in the literature      :
Although the signs and symptoms seen in radiation proctitis can point to a number of differential diagnoses, identifying prior pelvic radiotherapy for an underlying malignant disease during history taking must raise clinical suspicion of radiation injury. For this reason, a detailed patient history is perhaps the most important step in workup   . The course and the spectrum of symptoms should be assessed in order to determine whether chronic or acute forms of injury has occurred, after which imaging studies are employed. Non-invasive radiological investigations like ultrasonography, computed tomography, and magnetic resonance imaging are not useful in the initial evaluation of radiation proctitis, and invasive procedures, such as colonoscopy and rectosigmoidoscopy, are preferred  . A pale, friable mucosa with telangiectasias are typical findings, but it must be pointed out that biopsies are avoided when radiation injury is suspected, principally because of possible aggravation of bleeding and the development of other complications that could compromise the patient   . Additionally, recto-vesicular, recto-urethral or rectovaginal fistulas, considered as late-presenting signs of this disease, may also be confirmed during colonoscopy . Thus, the diagnosis of radiation proctitis relies on the history of prior radiotherapy, typical signs and symptoms, and macroscopic findings from invasive procedures.