Cytomegalovirus (CMV) colitis is an opportunistic virus typically diagnosed in immunocompromised patients. CMV proctitis is rarely reported in immunocompetent hosts. We describe a 71-year-old immunocompetent male who presented with persistent diarrhea and was CMV-negative on initial histopathology staining but was found to have severe CMV proctitis with rectal involvement diagnosed following repeat flexible sigmoidoscopy. CMV proctitis is likely an underrecognized cause of bloody diarrhea in the elderly. Early consideration of CMV proctitis in immunocompetent elderly patients with refractory colitis may prevent prolonged morbidity and unnecessary immunosuppressive therapy.