Thanks for adding the info...I definitely should have stated that using tap for an enema is (generally) a very bad idea for the reasons you mentioned.
Several years ago when I was just starting out with anal play, and naive about many things, I came across a video of a woman using a shower hose as an enema; the chick took it so far, she looked 3 months pregnant! Looked hot, and sounded intense, and - stupidly - decided to give it a try.
Definitely wound up with mild water intoxication. Firstly, felt like I'd had the worst bout of diarrhea ever (technically, I guess I did, LOL) - seemed like I was on the pot forever. Needless to say, wound up with quite a red, irritated ass, and anal play was the last thing I wanted to do. Symptoms included bloating and stomach ache, and I felt cold, weak and shaky...felt like I'd just had a bad stomach flu.
That being said, I typically always use tap water for quick 'rinses' after going to the bathroom..."mini-enemas," so to speak. Just enough to flush out the colon, especially before anal play. Never have any issues since it is only in there for a matter of seconds.
Humorous side note: apparently, there is a growing trend of college students ending up in the ER for intoxication due to a new(ish) fad of something called a "Mayan Beer Bong," in which the participant does a head stand, and the bong is inserted in the ass - as mentioned before, the intestines absorbs something like 200 times faster than the stomach, so it is like instant drunkenness.
[quote name='Rushy' date='27 August 2013 - 02:58 PM' timestamp='1377640708' post='873490']
Water intoxication can kill you and the colon is adapted to absorbing water. To prevent excessive water uptake you need to make the enema solution isotonic with the body fluids. This means adding 9g of common salt to each litre of water (a few % error will be OK but try and get this right). Alternatively, milk is a body fluid so you could use that as an enema so long as the processor hasn't fucked it about too much. The salty water soln is safer IMO. This rules out using the shower.
There are commercially available enemas that come in a small volume of liquid- these are more concentrated than body fluid (hypertonic) and rely on the movement of body water from the blood plasma into the colon by osmosis. That is, the fluid volume needed to generate a defaecation reflex comes from your own blood. Again, I think 0.9% NaCl soln is safer, cheaper, better.
That said, lots of people use water and it seems safe enough in practice- anyone had any bad experiences?
[/quote]