The programme is on Channel 5 at 20:00-21:00 on Tuesday 12 July according to
https://www.freeview.co.uk/tv-guide. The summary says "We'll hear first-hand stories from those who have experienced their worst holiday nightmares, as well as top tips from travel experts on how to avoid it happening to us."
I guess it will focus on airports and airlines and show lots of unhappy holidaymakers.