Don't get me wrong there are some bad days. Luckily people in the business are used to the nasty mess. On my good days my usual routine usually is making sure I do my bowl movement at least once a day to keep my pipes clean and moving. Usually I don't eat breakfast before I do a scene just in case it doesn't push whatever i ate last down further. Save the eating for afterwards, besides eating too much before sex leaves a nasty feeling. Then I empty out a enema, fill it with warm water. If nothing dirty comes out the first time then you should be fine. If you are dirty, try to enema with warm water a couple times and see if you can go to the bathroom. Don't use the actual solution in the enema. That'll make it worse than you've experienced. I've noticed too that if I'm really nervous at the moment, that's not a good time to have anal sex. Cuz the tension will only spurt out what you dont want coming. This is from my experiences so far. Hopefully you guys have luck.

Sorry if it sounds like a lousy process but it helps.