Giardiasis is a tummy bug that causes symptoms like diarrhoea, farting and bloating. It usually goes away in about a week if it's treated, but can sometimes last much longer.
There are lots of ways you can catch giardiasis, such as:
- drinking water that's not been treated to kill germs (usually while travelling in developing countries)
- water getting in your mouth while swimming in places like lakes, rivers or swimming pools
- eating food that's been washed in untreated water or handled by someone with the infection
- touching surfaces that have been touched by an infected person
- having sex – especially unprotected anal sex
You can become infected if small bits of poo from an infected person get in your mouth.
The main symptoms of giardiasis are:
- smelly diarrhoea
- tummy pain or cramps
- farting (flatulence)
- smelly burps – they may smell like eggs
- weight loss
You can also have it and be able to spread it to others without having any symptoms.
Call your GP surgery or 111 if:
- you have had diarrhoea for more than a week
- you have bloody diarrhoea or bleeding from your bottom
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
A pharmacist can help if you're dehydrated
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.
Page last reviewed: 10/10/2017
Next review due: 10/10/2020