A young adult man presented to an outlying emergency department with a sore throat, fever and chills. Upon failure of symptomatic management and a course of amoxicillin, he developed rectal pain and loose stools. Despite outpatient doxycycline treatment for presumed chlamydial proctitis, he developed worsening rectal pain and bloody stools. Results on abdominal and pelvic CT were consistent with proctitis. His symptoms worsened despite added metronidazole for bacterial proctitis. Workup revealed an elevated erythrocyte sedimentation rate, C reactive protein and calprotectin, suggestive of a diagnosis of inflammatory bowel disease (IBD). A colonoscopy revealed proximal tightness of the rectum, and pathology reported features suggestive of IBD. He was treated with prednisone and mesalamine. However, immunostaining positive for cytomegalovirus (CMV) confirmed a diagnosis of tissue-invasive CMV proctitis. This was further supported by serological testing for CMV consistent with a diagnosis of CMV proctitis preceded by a primary CMV infection of the pharynx.