Helminths of the Large Intestine

Helminthic infections of the large intestine are very common where poor water quality, inadequate sanitation, and overcrowding are present. Infection rates are highest in children with bad health habits and among immunocompromised individuals. Infection is mainly through the consumption of foods and drinks contaminated with infective stages, eating raw or undercooked vegetation containing parasitic stages, flies, and internal and external autoinfection. Helminths infecting the large intestine are associated with constipation and/or dysentery, abdominal colic, diarrhea, nausea, and vomiting, and also, pruritus ani (oxyuriasis), anemia, malnutrition, and indigestion. The following are the commonest parasites infecting the large intestine: