Symptoms of Giardiasis
Giardiasis typically presents with watery, foul-smelling diarrhea (without blood), abdominal cramps, bloating, flatulence, and weight loss, with symptoms lasting 2-6 weeks but potentially becoming chronic. 1, 2
Primary Gastrointestinal Symptoms
- Diarrhea is the most common symptom, characteristically watery, foul-smelling, and may be greasy or contain mucus (but never bloody) 1, 2, 3
- Abdominal cramps and pain occur frequently, often described as cramping discomfort in the abdomen 1, 2, 3
- Bloating and excessive flatulence are prominent features that distinguish giardiasis from other diarrheal illnesses 1, 2, 3
- Nausea and vomiting may occur in some patients 1, 4
Systemic and Chronic Manifestations
- Weight loss is common, particularly in chronic infections, due to malabsorption of nutrients 1, 2, 4
- Fatigue and general malaise are frequently reported according to the Centers for Disease Control and Prevention 1, 5
- Loss of appetite may accompany the gastrointestinal symptoms 6
- Steatorrhea (fatty stools) can develop due to fat malabsorption 4
Disease Course and Duration
- The infection typically lasts 2-6 weeks but can become chronic and may recur even after treatment 2
- Symptoms persisting beyond 14 days should raise strong suspicion for giardiasis, particularly in travelers 2
- The American Gastroenterological Association strongly recommends testing for Giardia in patients with chronic diarrhea (>11 days) 1, 7
Important Clinical Pitfalls
- Asymptomatic carriage is common - many infected individuals have no symptoms at all 1, 8, 4
- Symptoms mimic other conditions including irritable bowel syndrome, functional diarrhea, celiac disease, and small intestinal bacterial overgrowth 1, 2
- Symptoms can persist after successful treatment of the infection, which may confuse clinical assessment 1
- Immunocompromised patients (especially those with HIV) may experience more severe and prolonged symptoms 2