Preps vary a lot for pouchoscopy. For most purposes it seems to be sufficient to have clear liquids starting the previous afternoon (or the whole day, if you like), and tap water enemas (using an emptied Fleet’s bottle) before the procedure. I’d repeat the enemas until the output is pretty clean. Some people use various laxatives (Mag Citrate, etc.), but I don’t think that’s necessary to clean out a little J-pouch.

I had to do a fleet enema (the one your squirt into your pouch). It was easy and didn't cause me any trauma. I had to do it one hour before the procedure. Good luck!

Clear liquid meal prior to the procedure (no need for a full day, just be on clear liquid a few hours before).  Couple of Fleet enemas an hour before leaving the house.  It’s pretty easy, no need for all the mag citrate and colyte etc that a colonoscopy needs.

Theres another thread on this by someone else in General.  From that thread it sounds like it’s common for people to get varying instructions, particularly from staff that don’t know the custom needs of a pouch.  So if you’re told to do much more than above, I’d check in with the GI doc.