I've had occasional nasty pains that my Dr said were probably IBS. The leaflet that she gave me listed various probable causes - one was drinking cordial & I'd just started having Schweppes lime cordial or Barley Water in my usual water (my normal drink as I don't drink alcohol & don't like tea or coffee)
So I stopped drinking the cordial & had no more pains (mind over matter???)
Last Fri I asked barman for my usual Soda water with lemon (meaning a slice of lemon) - he said he had no lemon & would lime do (meaning cordial) & I didn't realise till I started drinking this very sweet drink (did I mention I don't like sweet stuff?) so I watered it down with a glass of tap water.
I'd totally forgotten about the IRB & cordials until I started getting nasty pains the next day.
Coincidence or not I'll make sure i don't have cordial again.