An 18-month-old Fjord gelding was examined for colic and clinical signs of tenesmus and dyschezia.Rectal examination and transrectal ultrasonography showed a firm tissue mass on the dorsolateral aspectof the left rectal wall. Histopathology of multiple perirectal tru-cut biopsies revealed a pyogranulomatousinflammation. Cultures for microorganisms were negative. A diagnosis of extra-luminal rectal pyogranulomatousinflammation was made. Conservative treatment resulted in complete remission.