How effective is antibiotic treatment for giardiasis?

Giardiasis is caused by a parasite affecting the digestive system. Treatment is selected according to symptoms, medical history, pregnancy, age, and local clinical practice. Loose stools, cramps, bloating, and tiredness may take time to settle even after the parasite has been treated.

Persistent symptoms do not always mean the medicine failed. Reinfection, another intestinal problem, or temporary difficulty digesting certain foods can cause ongoing discomfort, so clinicians may reassess rather than automatically repeat medicine.

Take the prescribed medicine as directed and drink enough fluid to replace losses from diarrhoea. Wash hands carefully after using the toilet and before preparing food. Clean bathroom surfaces and avoid preparing food for others while diarrhoea continues if advised.

Avoid untreated water and follow local advice about swimming or childcare. If several people in a household are unwell, mention this to a clinician, because shared exposure or person-to-person spread may need investigation.

Contact a clinician if diarrhoea persists after treatment, returns, or prevents normal drinking. Seek urgent help for severe dehydration, confusion, fainting, blood in stool, severe abdominal pain, or inability to keep fluids down.

Ask which medicine is appropriate, how to manage fluid loss, whether household contacts need testing, when a stool test is useful, and when normal activities can resume.