Do your research on this before proceeding. Enemas have killed people. The skin on the inside of the colon is very thin and easily scratched, which can allow faecal bacteria into the bloodstream. Further in, the lower regions of the large intestine are designed to soak liquid through to the bloodstream. for this reason alcohol enemas have killed people from alcohol poisoning. I'd be very wary of trying anything like tobasco sauce in there. Beyond the colon the digestive tract turns left, so if you lie on your right side during the administering of the enema the liquid is unlikely to go "up" to the left side of your body and move into the large intestine. Not much of a problem if it does of course providing the liquid is pretty benign stuff... but if you do lie on your left hand side you need to be ready to expel some fairly fierce smelling stuff: it ain't pleasant that far in. Physically, use masses of lube and go slow. there are two sphincter muscles holding your anus closed. The outside one is fairly easy to coax open but the inner one can be like fort knox on some people. Forcing will cause very non-erotic pain; gentle persuasion does it. :-)