Intestinal parasites are various micro-organisms that can cause very unpleasant consequences in the intestinal tract and anal area. Infections with amoebae, the small intestine parasite Giardia lamblia and threadworms are particularly common. They can be transmitted through foodstuffs, but also via sex.
In people with HIV, an infection with Giardia lamblia is usually more serious, with more severe symptoms. In HIV-positive people, it is more common for the pathogen to enter the pancreas and gall bladder. This leads to inflammation with strong cramp-like pain in the upper abdominal area, severe nausea and vomiting.