Additional information to obtain includes recent travel history, changes in medications (including addition of antibiotics), recent hospitalizations, changes in diet, social history, recent infections (or history of prior infections), last dose of RT, pertinent family history, and whether the patient has ever had a colonoscopy (and if so, the results). A basic initial workup could include a comprehensive metabolic panel, complete blood count with differential, and stool studies.

Blood tests such as C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) are relatively non-specific inflammatory markers and may not provide much benefit pending the patient’s clinical presentation.

If, based on the above workup, radiation colitis is still high on the differential diagnosis, patients may undergo a flexible sigmoidoscopy (FS) or colonoscopy to further evaluate the mucosa and obtain biopsies. An FS can typically evaluate only the left side of the colon, while a complete colonoscopy evaluates the full colon and can usually enter the terminal ileum, which is an important structure to evaluate in patients with diarrhea, bleeding, and changes in bowel habits. An FS is a shorter procedure, does not require the full colonoscopy prep, uses a smaller caliber endoscope, and usually requires 1 to 2 enemas prior to the procedure.

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Endoscopically, radiation colitis can appear non-specifically, with erythema, erosions, ulcerations, and friability. Biopsies can be taken of the mucosa and sent for analysis to rule out infection and attempt to clarify the underlying cause. There are no pathognomonic findings for radiation colitis on biopsy, though the results are crucial in ruling out other causes. Some research is being done to develop a histologic classification system, though it is not widely used.5

Once a patient is diagnosed with radiation colitis, there are multiple treatment options.6 Options for patients with tenesmus, diarrhea, and bleeding include short chain fatty acid, hydrocortisone, and sucralfate enemas.

For patients with chronic radiation colitis with anemia and bleeding refractory to medications, argon plasma coagulation (APC) therapy can be delivered endoscopically. APC uses argon gas to provide heat to the mucosa in a way that contact with the mucosa is not needed for hemostasis. Most patients will require multiple sessions of APC in 1-month intervals to help alleviate their symptoms.

References

  1. Pollack JM. Radiation therapy options in the treatment of prostate cancer. Cancer Invest. 2000;18(1):66-77.
  2. Shadad AK, Sullivan FJ, Martin JD, Egan LJ. Gastrointestinal radiation injury: prevention and treatment. World J Gastroenterol. 2013;19(2):199-208. doi: 10.3748/wjg.v19.i2.199
  3. Tagkalidis PP Tjandra JJ. Chronic radiation proctitis. ANZ J Surg. 2001;71(4):230-7.
  4. Beard CJ, Propert KJ, Rieker PP, et al. Complications after treatment with external-beam irradiation in early stage prostate cancer patients: a prospective multi-institutional outcomes study. J Clin Oncol. 1997;15(1):223.
  5. Goldner G, Tomicek B, Becker G, et al. Proctitis after external-beam radiotherapy for prostate cancer classified by Vienna Rectoscopy Score and correlated with EORTC/RTOG score for late rectal toxicity: results of a prospective multicenter study of 166 patients. Int J Radiat Oncol Biol Phys. 2007;67(1):78-83.
  6. Hanson B, MacDonald R, Shaukat A. Endoscopic and medical therapy for chronic radiation proctopathy: a systematic review. Dis Colon Rectum. 2012;55(10):1081-95. doi: 10.1097/DCR.0b013e3182587aef