Gastrointestinal tract bleeding caused by cytomegalovirus: A comprehensive review

Cytomegalovirus (CMV) infections of the gastrointestinal tracts most commonly affected the colon, followed by the small intestine and esophagus. The clinical presentation is largely dependent on the infected site. Odynophagia is almost present in CMV esophagitis. Hematemesis can occur in CMV esophagitis, gastritis and duodenitis. CMV ileitis and colitis may manifest with fever, abdominal pain, watery diarrhea, bloody stool as well as abdominal distension due to paralytic ileus or even perforation. Gastrointestinal tract bleeding can be self-limited, but may recur intermittently. Massive bleeding and intestinal perforation can be lifethreatening. CMV is more likely to be pathogenic in patients with steroidrefractory ulcerative colitis. CMV colitis could be concurrently with or following the treatment for the patients infected by Clostridium difficile. Duodenal bleeding unresponsive to proton pump inhibitors could be due to CMV duodenitis. Diagnosis of CMV disease relies on endoscopic biopsies. Histology typically shows viral inclusions, referred to as owl's eyes. The immunohistochemical staining to detect CMV antigen is a more sensitive method. The CMV polymerase chain reaction (PCR) or the CMV antigenemia assay can be used as an alternative method to diagnose CMV disease and to monitor effectiveness of treatment. CMV-PCR for the blood, stool or gastric juice may offer a screen method of diagnosis. Therefore, a programmatic approach could be applied for the diagnosis of CMV gastrointestinal disease. The outcome of CMV disease in the intestine is generally favorable by the treatment consisting of intravenous ganciclovir or oral valganciclovir. Massive bleeding and perforations require surgical resections of the infected sites.