Gastrointestinal disease is a significant cause of morbidity and mortality
in the immunocompromised patient. This article focuses on the infectious ga
strointestinal complications associated with the treatment of malignant dis
ease and with solid organ transplantation but not HIV. Gastrointestinal def
enses and the various mechanisms by which they are impaired are reviewed. T
he major pathogens and malignancies of this patient population and an appro
ach to their diagnosis, treatment, and prevention are discussed.