[Anorectal ulcers--etiology, diagnosis, therapy (simple rectal ulcer, radiogenic ulcer, CED].

Ulcers of the anorectal region are very variable in etiology and morphology. Often differential diagnosis is even possible by (excisional-)biopsy. As they are symptoms of any kind of disease, therapy has to be derived from this disease. Therefore surgery often only plays an additional part besides clearing the diagnosis, although the surgeon is mostly the first consultant, so being responsible for ongoing therapy. Some special diseases, their problems and therapeutical options, are described in detail.