INTRODUCTION

Acquired immunodeficiency syndrome (AIDS) has become a pandemic, resulting in 25 million deaths and 40 million persons infected with the AIDS virus. The disease prevalence is particularly high in developing countries. The enormity of the problem is highlighted in the sub-Saharan African continent, which represents only 10% of the world’s population, but constitutes 77% of AIDS deaths.

Clinical advances have evolved in consonance with a greater understanding of the virologic and immunologic markers of disease stage, mechanisms of viral transmission and the problem of viral resistance to antiretroviral drugs. Gastrointestinal and hepatobiliary complications are important components of the HIV/AIDS syndrome. They are common and affect most patients with AIDS during the course of their illness.

MALNUTRITION AND CACHEXIA

Survival in AIDS patients is strongly associated with nutritional status. Weight loss is a cardinal feature of AIDS. The factors contributing to weight loss include anorexia, inadequate oral intake, intestinal malabsorption and alterations in metabolism and endocrine dysfunction.

Reduction in oral intake allied to anorexia is a critical factor in weight loss. Malnutrition also has deleterious effects on the immune system. Careful assessment of the patient and the diagnosis, with treatment of systemic illness or upper gastrointestinal disease, usually results in weight gain.

Nutritional supplementation in the form of appetite stimulants and enteral alimentation often leads to a greater feeling of well-being. Total parental nutrition may be indicated in some cases.

CHRONIC DIARRHOEA

Because of the wide spectrum of potential infections that may cause diarrhoea (Table 22.1), it is appropriate to have a systematic approach in investigating the aetiologic agent/s (Figure 22.1; Table 22.2). Weight loss and diarrhoea suggest an opportunistic infection, malabsorption or small bowel bacterial overgrowth. Severe watery diarrhoea suggests cryptosporidiosis. Diarrhoea with nausea and abdominal pain may indicate Giardia, Isospora belli or Mycobacterium avium. Rectal bleeding may indicate viral or bacterial colitis or Kaposi’s sarcoma.

TABLE 22.1 Common causes of diarrhoea in AIDS

FIGURE 22.1 Assessment of diarrhoea in AIDS.

Based on Wilcox CM. AIDS and the gut. In: Weinstein WM, Hawkey CJ, Bosch J, eds. Clinical gastroenterology and hepatology. Philadelphia: Mosby; 2005:8331–6, with permission.

TABLE 22.2 Assessment of diarrhoea in AIDS