A worldwide infection, particularly common in the tropics, caused by Trichuris trichiura, or whipworm, so-called because of its shape – the rear end being stout and the front end hair-like, resembling the lash of a whip. The male measures 5 cm and the female 4 cm in length. Infection results from eating vegetables, or drinking water, polluted with the ova (eggs). These hatch out in the large INTESTINE and the diagnosis is made by finding the eggs in the stools (FAECES). The worms seldom cause any trouble unless they are present in large numbers when, especially in malnourished children, they may cause bleeding from the bowels, ANAEMIA and PROLAPSE of the RECTUM. The most effective drug is MEBENDAZOLE.