Request an online visit for Giardiasis. A licensed provider reviews your case and prescribes treatment when appropriate.
Board-Certified · Internal Medicine · Medical Director
All 50 states + DC·Video visit
In-network: Aetna, BCBS, UnitedHealthcare +18 more plans
Giardia duodenalis is a protozoan parasite acquired from contaminated water, food, or fecal–oral contact. It causes prolonged watery or greasy diarrhea, abdominal cramps, bloating, malabsorption, fatigue, and weight loss; some carriers remain asymptomatic. Risk is higher with international travel, camping, day-care attendance, and certain water exposures. Diagnosis is by stool antigen or PCR. Treatment is oral tinidazole, metronidazole, or nitazoxanide. Persistent symptoms after treatment may reflect post-infectious irritable bowel syndrome or lactose intolerance rather than treatment failure.