Giardia or Giardia Lamblia is a tiny parasite that lives in the intestine of people and animals. Giardia has become recognized as one of the most common causes of waterborne disease (drinking and recreational) in humans. Giardia may be found in soil, food, water, or surfaces that have been contaminated with the faeces from infected humans or animals. It occurs worldwide but is particularly prevalent in the tropics. It is an important cause of traveller’s diarrhoea.