The pathogenicity of cytomegalovirus in inflammatory bowel disease: a systematic review and evidence-based recommendations for future research.

During recent years, a clear association between complicated courses of ulcerative colitis and the presence of cytomegalovirus (CMV) has been established. The exact pathogenic role of CMV in these patients remains unclear despite a great number of published reports. Therefore, we undertook a systematic review to appraise critically all available evidence in the literature on the role of CMV during inflammatory bowel disease.