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Giardiasis may cause foul-smelling watery diarrhea, bloating, flatulence, steatorrhea, weight loss, or chronic malabsorption, although infection can be asymptomatic. Exposure risks include contaminated water or food, daycare settings, travel, and some sexual practices; IgA deficiency and malnutrition are among the listed risk factors. Diagnosis may use stool testing, antigen tests, or nucleic acid amplification, with duodenal aspirate considered when suspicion remains high despite negative results. The source outlines tinidazole as first-line therapy and lists alternative agents, pregnancy considerations, counseling, and approaches to treatment failure. Post-therapy management and public-health measures—including safe water practices and hygiene—are also important parts of care.