Say I drink a bunch of water, wait until I have to pee real bad, then go for a run in Death Valley. Can my body reclaim that water directly, or do I have to pee it out and drink it?
My understanding is that, yes, you can reclaim water in your bladder. This is why the best place to store water when you’ve got a limited amount is in your body.
On a similar note, I read just recently where a family was stranded in a boatwreck, and the only water available was in the bilge- really nasty, undrinkable water. Luckily, the mother is a nurse, and knew enough to give her families enemas with the water- they were able to absorb the water through their colons, without having pass it (heh) through their entire digestive systems.
I believe that I would just as soon die of dehydration than have my mother give me an enema with filthy bilge water.
The cells lining the human bladder are not able to capture free water from the urine. Once urine has passed down the ureters, it is essentially retained in the bladder until it is peed out.
It is not uncommon to have an elderly patient who is markedly dehydrated but has urinary retention (usually mechanical, at the level of the prostate) with a very full bladder.
Is this for real? Will it work? Would it work with salt water?
if you had a salt water enema i would think it might pull water out of your body.
Well, you can only “reclaim” it by peeing and then drinking it.
Hang on. If this water was “undrinkable,” presumably because it had either bacteria or chemical contamination rather than just tasting yucky, then why would be OK to absorb it through your colon?
Salt water presents a problem no matter which end it goes in. The trouble occurs when the salt is absorbed in solution, and that happens in your colon whether you drink it or pump it in.
Dunno. Just reporting what I’d heard.
Wrong on both counts, however.
This would seem to indicate that water can, in fact, be absorbed through the colon.
As for reabsorption through the bladder, looks like I’m wrong on that. Although frogs, apparently, can do so.
While water can be absorbed through the colon wall, there is no particular reason why a colon route would render contaminated water any safer than an oral route; in fact, to some extent the acidic nature of the stomach is toxic to some pathogens. If the fluid being drunk were so vile as to cause retching, I suppose one could make a case for an enema, but I doubt the veracity of any such story…
Of course water can be absorbed through the colon.
But as Chief aptly pointed out, it’s no better than using the oral route for fluid ingestion, and may be worse, unless one is unable to ingest fluids orally.
Well, what’s safer for human feces: an oral route or a colon route? Hm. Obviously the colon is safer for one’s own feces. I could see it going either way for somebody else’s, but I’m going to guess colon (perhaps I’m being fooled because it seems less gross).
Are you asking if it’s better to eat/drink someone else’s feces vs. receiving said feces via an enema?
If so, I’d still opt for the former route, as the acid in the stomach will break down some pathogens. But either way, taking in someone else’s colonic bacteria is still a risky maneuver, no matter which way you take it in.
IMHO, anyway. I admit I’m shying away from contemplating the dichotomy in much depth.
C’mon, doc, where’s your sense of discovery? 
Yes.
(And what’s with all the said [noun] on the SDMB, when it or the [noun] would do just fine?)
I’m not recommending it. It was just a thought experiment to get at the claim about bilge water.
In fact absorption of water is the colon’s primary purpose. It just usually enters the colon through the other end.
I suspect the Pedant has had even fewer coprophagics in his patient population than QtM (granted some of QtM’s coprophiles may be involuntary ones…). Nevertheless, if it comes to it, I’d argue an oral route is probably safer if you get the stool munchies for stool from any source, because the stomach is at least marginally hostile to some pathogens.
Back on the bilgewater front: dumping pathogenically-contaminated water into a colon is gonna be a ticket for sepsis, and putting chemically-contaminated water into a colon is no safer than an oral route. So I again dismiss that story as apocryphal–or, at least–the fact that the colon route was safer somehow as incorrect, regardless of outcome.
Yeah, put me down as another vote for rather eating feces than taking it via an enema.
Mishandling of foods happen every day-so it’s easily more than likely that you’ve eaten some feces while dining out. I’d much rather face that than have it directly introduced into my colon.
the exposure time vs. route could be compared.
the stomach would have some beneficial effect on breaking down some of the pathogens, unknown effect on other toxins, if you didn’t puke then it has a longer transit time through the body.
anally it would be able to have less disturbed absorption there but also a shorter retention time which could be short with the fluidity and increased colon pressure with the bilge water enema.
maybe similar for the fecal loading.