Image of Radiation Proctitis in the NEJM:
One thing I find a little concerning about this is that in the caption, it is implied that they biopsied the lesion to establish the diagnosis of proctitis. We never recommend this unless these is concern of cancer, as any injury to previously irradiated tissue, especially tissue already demonstrating late effect, can have unintended complications. Having seen fistulas formed after biopsy in similar cases, I would recommend treated clinically based on the history and appearance from the colonoscopy.
Radiation Proctitis: "New England Journal of Medicine, Volume 363, Issue 12, Page 1163, September 2010."