Giardia lamblia in human duodenum, illustration - stock illustration

Giardia lamblia in the human duodenum, computer illustration. Giardia lamblia is single-celled protozoan that has flagellae for motility. It causes the disease giardiasis (or lambliasis), an infection of the small intestine most common in tropical areas. Giardia lamblia attaches by means of sucking discs to microvilli in the human intestine. Abdominal cramps, bloating, diarrhoea and nausea may occur. The organism is spread by direct contact or through contaminated food and water.