1. Introduction

Infection with the human immunodeficiency virus (HIV) and the development of the acquired immunodeficiency syndrome (AIDS) represents a significant problem worldwide. As of the end of 1994 it was estimated that over 17 million persons worldwide were infected with the HIV. In Canada, it is estimated that over 30,000 persons are infected with the HIV, giving an approximate prevalence of 191/100,000. The clinical manifestations of HIV infections and AIDS are varied and can involve all organ systems. The gastrointestinal (GI) tract is a common site for opportunistic infections and neoplasms in patients with HIV infection. Over 75% of patients will have significant symptoms related to the gastrointestinal tract at some point during the course of their infection. In many patients GI involvement represents the major manifestation of their HIV infection.