Case Presentation: A 59 y/o male who presented to the hospital with a 2 week history of subjective fevers, generalized fatigue, and non-bloody diarrhea. Past medical history was notable for indeterminate ulcerative colitis (UC) and was being managed with azathioprine and mesalamine. He was recently prescribed antibiotics and developed diarrhea shortly after. He denied any rash, abdominal pain, melena, or rectal bleeding. On presentation, he was febrile with all other vital signs normal. Labs showed a normal wbc count, low platelets, hyponatremia, hypokalemia, and low albumin. Liver enzymes, bilirubin, lactic acid and fecal calprotectin were mildly elevated. CT-AP on admission revealed transverse colitis along with thrombus at the portal vein confluence and the inferior mesenteric vein. Anticoagulation was started along with empiric antibiotics for murine typhus given patient’s endemic risk factors but was ruled out comprehensive infectious disease workup. A UC flare was also ruled out due to lack of clear positive findings on history and exam. CT-chest ruled out lymphoma, but noted a new thrombus in the portal vein. Pylephlebitis was suspected, however fevers continued to persist after antibiotics were optimized. CMV PCR returned positive with >5 million copies/ml and CMV colitis confirmed on biopsy without signs of active IBD. IV antivirals were initiated and his fevers started to resolve along with reducing viral burden. He was eventually transitioned to oral antiviral therapy and was discharged with resolution of his symptoms.

Discussion: Cytomegalovirus (CMV) is a ubiquitous and opportunistic pathogen that can take advantage of an immunocompromised host. This patient did not initially present with many of the frequently observed symptoms seen in CMV colitis such as hematochezia and abdominal pain. The venous thromboembolism (VTE) noted on imaging was initially attributed to the pro-inflammatory state of IBD, however are noted to be a rare complication of CMV. Many of the symptoms can be overlapped with inflammatory bowel disease (IBD) and other infectious etiologies which delayed diagnosis.

Conclusions: CMV colitis should be considered as a differential in IBD patients who present with fever, VTE, and non-specific symptoms of systemic illness.