Giardiasis
An intestinal infection caused by a parasite that spreads through contaminated water, food, or hands.
Common symptoms
- Watery diarrhea
- Greasy stools
- Stomach cramps
- Gas
- Nausea
- Weight loss
Cause
Giardia lamblia parasite, common in daycare outbreaks and untreated water.
How common is it?
Most common intestinal parasite in the U.S.; frequent in daycare and camp settings.
Treatment
Prescription antiparasitics (metronidazole, tinidazole, or nitazoxanide) and rehydration.
Prevention
Thorough handwashing after diapering and toilet use, safe drinking water when camping, avoiding swallowing pool or lake water.
See what's going around
Track Giardiasis and other illnesses at your child's school in real time.
Frequently asked questions
Giardiasis articles for parents
- October 2025When Should Kids Stay Home from School?Guidelines to help parents make the tough call about keeping sick kids home.
- December 2025Managing School Sick Days: A Chicago Working Parent's Survival GuideWhen your child is sick and you have work, something has to give. Practical strategies for Chicago parents juggling careers and caregiving.
Related illness guides
Medical disclaimer: Educational only. Always consult a healthcare provider for diagnosis and treatment.