Had Picolax twice now for 2 barium ennemas, and also a camera down my throat at a different time, none hurt.
Firsly the picolax is a bit like drinking sand, a bit grittty, and weird tasting,wear a trackie bottom or pair of shorts, as when the urge comes its not the head of a turtle,but a flood of ginormous proportions,then just dirty water for some reason,this may reqire a repeat run to the toilet a few minutes latter.
Next day you usually take the next Picolax and the same thing happens.
No pain,but you cant eat anything.
As for the Colonoscopy i refused as i felt better,and nothing showed up on the barium enemas thankfully.
Hope everything turns out ok for you.