flax,
the prep is the same. It is good to acertain that there isn't additional damage in the colon. Considering the angle of the beams with your cancer treatment your doctor might consider rectoscopy. My cancer was rectal.
It would be nice if they let you schedule both at the same time, so you'd only have one prep.
Was it easy for you to find a gastroenterologist for the Halo?
I'm delighted you were able to find a practitioner. Was it easy.