Aetiology

Homosexual HIV infected patients are also susceptible to sexually acquired organisms causing the gay bowel syndrome.

Other causes include:

Bacteria:

• Salmonella acquired from food is the most common bacterial cause of diarrhoea
• Campylobacter acquired both sexually and from food is the second most common bacterial cause.

Protozoa:

• Cryptosporidia is the commonest opportunistic cause of diarrhoea in HIV infected patients.
• Microsporidia and Giardia may also cause diarrhoea

Viruses:

• cytomegalovirus
• Adenovirus may also cause viral diarrhoea, though this occurs principally in immunosuppressed children and is relatively rare in HIV-positive patients.