There are lots of ways you can catch giardiasis, such as:
You can become infected if small bits of poo from an infected person get in your mouth.
The main symptoms of giardiasis are:
You can also have it and be able to spread it to others without having any symptoms.
It's best to call rather than visit a GP surgery as you might have an infection that can spread easily to others.
Tell the GP if you have recently travelled abroad.
Your GP may send off a sample of your poo for tests to check if you have giardiasis.
It's treated with antibiotics for a few days. Your symptoms should stop in about a week, but they can sometimes last longer.
Go back to a GP if you still have symptoms a week after starting treatment.
They might give you more antibiotics or refer you to a specialist for treatment.
Sometimes the people you live with may also need to be tested and treated.
You're most infectious from when your symptoms start until 2 days after they have passed.
Stay off school or work until your symptoms have stopped for 2 days.
While you're recovering:
drink lots of fluids to avoid dehydration, such as water and squash – if you're well hydrated, your pee should be light yellow or clear
give your baby breast or bottle feeds as usual if you or your baby are ill
wash your hands with soap and water frequently
wash dirty clothing and bedding separately on a hot wash
clean toilet seats, flush handles, taps, surfaces and door handles every day
do not drink alcohol while taking your antibiotics – alcohol can react with the main antibiotics used to treat giardiasis
do not prepare food for other people, if possible
do not share towels, wash cloths, flannels, cutlery and utensils
do not use a swimming pool until 2 weeks after your symptoms stop
Speak to a pharmacist if you have signs of dehydration, such as peeing less than usual or having dark, strong-smelling pee.
They may recommend using sachets that you mix with water to help you stay hydrated, called oral rehydration solutions.