[en] Condyloma acuminatum (CA) is a manifestation of Human Papillomavirus (HPV) infection which usually occurs in genital and perianal regions. We report a 46-year-old man with an ulcerative proctitis diagnosed four years earlier, asymptomatic for a long time under azathioprine but without any follow-up for three years. A colonoscopy was performed prior to potential immunosuppressive treatment discontinuation and showed a circumferential “laterally spreading tumour” in the rectum. Surprisingly biopsies revealed a CA with a very focally high-grade intra-epithelial lesion. Azathioprine was stopped and a transanal surgical resection was performed. At guided anamnesis, patient confirmed to be a former active “men who have sex with men”. No recurrence of proctitis occurred despite azathioprine discontinuation. A retrospective review of the histological sections suggests that it was, in fact, an intestinal spirochetosis misdiagnosed as inflammatory bowel disease. Involvement of the rectal mucosa by HPV is a rare condition and this may have been promoted by inappropriate immunosuppressive treatment.