Cytomegalovirus (CMV) causes infections in healthy individuals and compromised hosts. In compromised hosts, CMV may cause encephalitis, pneumonia, hepatitis, colitis, and so forth. In immunocompetent hosts, CMV mononucleosis is the most common clinical manifestation and CMV colitis is rare. We present a case of an 82-year-old immunocompetent man who presented with community-acquired bloody diarrhea. A computed tomography scan of the abdomen revealed pan-colitis. His age and abdominal pains suggested ischemic colitis as the cause of his bloody diarrhea. Workup for Clostridium difficile and all enteric pathogens were negative. The patient remained febrile with abdominal pain. During the second week, he underwent sigmoidoscopy for biopsy, which revealed viral inclusions of the Cowdry owl eye inclusion bodies characteristic of CMV. CMV colitis was diagnosed in the patient; he was successfully treated with a course of oral valganciclovir and made an uneventful recovery.