Giardia is a tiny parasite (germ) that causes the diarrheal disease giardiasis. Giardia is found on surfaces or in soil, food, or water that has been contaminated with feces (poop) from infected people or animals. Giardia spreads easily and can spread from person to person or through contaminated water, food, surfaces, or objects. The most common way people get sick is by swallowing contaminated drinking water or recreational water (for example, lakes, rivers, or pools). Key words: Giardia lamblia, parasites, enteroscopy, fatigue, nausea, diarrhea, abdominal cramps, weight loss