Agree with all the above. One thing to remember about the bowel is that it is the primary place where water (in the form of gastric and pancreatic juices as well as in the form of liquid drunk with food) is reabsorbed into the body. It is therefore histologically and physiologically good at absorbing liquids.

There are also stories out there about alcohol enemas and these are also very dangerous to do as the absorption rate of alcohol in the bowel is a lot more efficient than anywhere else in the body (and it is bad enough when you spray alcohol into the air and accidently breath it in while working in a microbiology lab... ) . You therefore get drunk a lot quicker - often to dangerously toxic levels without you knowing. I have seen some pages discussing wine enemas and they all suggest a mix of wine and water that is mostly water. I do not condone doing this but if you do want to experiment with it I suggest you check out safe ways to do it.

With regards to IBS... yes, check with a doctor before you do anything. However, if you do have IBS (which is doctorese for 'there's something wrong with your bowel but buggered if we know what it is'), then you may be interested to know that at least one person I know has reported the IBS symptoms more or less completely vanishing for a short while (several months) following an enema that was given in preparation for an investigation. Clearly the enema had flushed something out that was causing the irritation.

Incidentally, piece of trivia, one of the standard military procedures for treating hypothermia is to use a warm water enema to quickly warm the body core.