How long does antibiotic treatment take to work for giardiasis?

The infection can irritate the small intestine, so stool changes may outlast the active infection. Temporary difficulty digesting certain foods can also leave gas or loose stools after treatment. Persistent symptoms may reflect reinfection, treatment failure, or another digestive problem, and they deserve review rather than repeated self-treatment.

Take the prescribed medicine exactly as directed and drink fluids regularly. Wash hands carefully after using the toilet and before preparing food; clean shared bathroom surfaces and avoid preparing food for others while diarrhoea continues. Avoid swallowing untreated water, and ask a clinician how to manage milk or other foods if they worsen symptoms. Read about [Giardiasis](/conditions/giardiasis/) and [Antibiotic Treatment](/treatments/medical-management/antibiotic-treatment/).

Contact a clinician if diarrhoea does not settle after treatment, returns, or prevents normal drinking and eating. Seek urgent care for signs of dehydration such as very little urine, marked dizziness, confusion, or inability to keep fluids down. Blood in the stool, severe abdominal pain, or a high fever also needs prompt assessment.

Ask whether you need repeat stool testing, when it is safe to return to food preparation or childcare, which fluids are suitable, and whether ongoing symptoms suggest temporary food intolerance or another cause.