[Intestinal parasite infections].

Symptoms in a diarrhea patient are most commonly due to a virus or a bacterium, but they may also be caused by a parasite. A long incubation period is typical of intestinal parasite infections, and in addition to diarrhea they cause prolonged symptoms such as abdominal pain and nausea. Parasitic cyst forms are secreted with feces and are highly tolerant against various environmental conditions. The infections are caught via fecally contaminated food or drink. The diagnosis is based on a formalin-fixed fecal parasitic specimen, leading to further investigations when necessary.