Streptococcus bovis is normally found in the gastrointestinal tract of the human population. The
association between Streptococcus bovis and bowel neoplasia has been frequently reported. This
report presents two cases of total hip arthroplasty with Streptococcus Bovis infection at 18 and 11 years after arthroplasty. The diagnosis was made with the help of clinical findings, standard radiographs, and laboratory tests (complete blood count, C-reactive protein, sedimentation rate, and the hip aspiration). Infections were treated by implant removal and antibiotic spacer implantation. Intravenous antibiotics were administered for 12 weeks. Revision arthroplasty was performed when laboratory tests (complete blood count, C-reactive protein, sedimentation rate) were within normal limits. Streptococcus bovis infection prompted the authors to investigate for any bowel malignancy. Colonoscopy and transrectal biopsy revealed adenocarcinoma in case 1, while case 2 had prior diagnosis of flat polyps in the colon. There are a limited number of reports in the literature reporting the presence of Streptococcus bovis infection concurrent with arthroplasty and bowel malignancy. These two case reports highlight the possibility of hematogenous seeding of arthroplasty components by Streptococcus bovis in patients with colonic neoplasia. Streptococcus bovis infection of hip arthroplasty may provide an opportunity for diagnosis of colonic neoplasia. Acute hip pain in patients with hip endoprostheses and simultaneous bowel malignancy should be evaluated promptly for hematogenous infection by standard radiograph, complete blood count, C-reactive protein, sedimentation rate, and hip aspiration.