Chlamydia Trachomatis Colitis in an Aged Male Homosexual

: An 83-year-old male was admitted to our hospital complaining of hematochezia and anal pain. He was an active homosexual. His physical examination was normal except for anal pain and bloody stool which were discovered on digital examination. Serum samples showed positive antibodies to Chlamydia trachomatis (C. trachomatis) by EIA. Stool cultures were negative for pathogenic bacteria and parasites. A colonoscopy revealed multiple aphthous erosions in the rectosigmoid and ileocecal regions. The histological findings were non-granulomatous colitis with inflammatory cell infiltration and atrophy of the glands. An immunohistological staining of biopsy specimens was positive for C. trachomatis. Antibiotic therapy was an effective treatment for the symptoms. This case appears to be a nonlymphogranuloma type C. trachomatis infection to the large bowel. Ileocecal lesions have not been reported in non-lymphogranuloma type C. trachomatis colitis.