The symptoms of giardiasis usually begin 4-10 days after a giardiasis infection has occurred, but they can appear up to three weeks later.
They can begin suddenly and abruptly or they can develop slowly over the course of a number of days.
Initial symptoms can include:
- watery diarrhoea, which can be foul-smelling and explosive
- abdominal cramps
- vomiting
- a mild high temperature of between 37-38ºC (98.6-100.4ºF)
- producing foul-smelling wind (farts)
- nausea (feeling sick)
- bloating
- indigestion
- fatigue (extreme tiredness)
- loss of appetite
- weight loss, which can be as much as 4.5kg (10 pounds)
If left untreated, the symptoms can persist for around one or two months before gradually improving.
A small number of people go on to develop long-term (chronic) giadiasis, which causes persistent or repeated bouts of diarrhoea that can last for up to two years. In children, long-term giardiasis can result in a failure to grow at the expected rate. The medical term for this is failure to thrive.
However, long-term giardiasis is rare among people who have been treated for the condition.
When to seek medical advice
Visit your GP if you have symptoms of diarrhoea, cramps, bloating and nausea that last for more than a week.
If your child has diarrhoea, contact your GP if your child passes six or more watery stools in the space of 24 hours, or if their symptoms of diarrhoea persist for more than five days.
