Enema Play on the Go

I used to give myself two or three bag enemas on a fairly regular basis before I moved in with my other half. I don't do much more than a Fleet enema or small bulb one before anal play these days, but haven't lost my love for that lovely full feeling a bag full gives. I have always wondered how people manage to have a large volume enema away from home, say in a play session at someone else's place or in a hotel. I once had a colonoscopy in a hospital in north London and had to travel home about an hour on the Tube after a Fleets and I really sweated the idea that I might need to go suddenly without a toilet near at hand. So what would work for a good old-fashioned clean out before travelling home?