Entamoeba coli, E. hartmanni, E. polecki, Endolimax nana, and Iodamoeba buetschlii are generally considered nonpathogenic and reside in the large intestine of the human host. Both cysts and trophozoites of these species are passed in stool and considered diagnostic. In the school year 2002/2003 there were examined in Poland some of the population of 7-year-old children for the presence of intestinal parasites, continuing countrywide operation launched in 1988.The studies included 31 504 children from 15 provinces of Poland. The overall percentage of the infected children was 15.4%. The highest number of infected children was found in the province warmisko-mazurskie (29.6%0), the smallest in slaskie (8.8%).
Prevention of the disease is by separating food and water from faeces and by proper sanitation measures. With colonoscopy it is possible to detect small ulcers of between 3–5mm, but diagnosis may be difficult as the mucous membrane between these areas can look either healthy or inflamed. Many intestinal protozoa parasites inhabit the gastrointestinal tract of humans. However, majority of them are non-pathogenic commensals or only result in mild disease while a few of them such as Cryptosporidium parvum (CP), Entamoeba histolytica (EH) and Giardia lamblia (GL) are pathogenic and have been associated with human gastrointestinal disorders worldwide among children and adults alike