I was home from Kenya 8 days when i started to feel a bit iffy. As im prone to upset tums I didnt take much notice at first but after a few days I might as well have camped out in the bathroom ... have barely left the house in over a week it has not been pleasant.
Gp insisted on tests and it seems I bought back a couple of parasites one of which was Giardia lamblia - mostly got from infected water. Just as likely from a pool as well as anywhere else it seems.
This nasty little fella can stay dormant for up to a month after infection so if you start getting travelers tum some time after hols its worth getting checked out as without traetment its unlikey to go away.