Herpes simplex virus (HSV) is a well-recognized cause of gastrointesti
nal infection, most commonly in patients with underlying immunodeficie
ncy. The esophagus, perianum, and rectum are the most common sites of
involvement; however, extensive colitis is rare. We describe a woman w
ith Crohn's disease who developed pathologically proven HSV colitis. W
e review the literature and present the possible implications of this
diagnosis.