I have wondered many times how a human would fare if the kidneys dumped urine into the start of the large intestines somewhere about the appendix instead of into a bladder to be sprayed out. I’m assuming water would be reabsorbed and slower to process out, primarily through sweat and evaporation from the lungs, and maybe diarrhea, though it may be that other waste products, such as salts or ureas may be absorbed into the large intestines instead of being ejected, though I have no idea if it would, or if it would be ejected as intended. Do we have any biologists here that could give insight on if combining both waste paths into one would be advisable?
Consider, for a second, what would happen if and when the pressure in the colon exceeded the pressure in the bladder, and a urethra connected the two: fluid in the colon would backfeed into the urinary tract. The kidneys would ultimately be exposed to intestinal flora.
The prevalence of UTIs even with the “air gap” of separate waste streams tells me that this would be an extraordinarily bad idea.
readyno@lemmy.world 7 months ago
Am doctor, you are essentially asking about a fistula (abnormal communication) that would allow urine and bowel to mix. This would allow for communication of gut bacteria to then invade the urinary system which would then easily cause a kidney infection which would then seed the blood resulting in bacteremia. Bacteremia is bad, like you die from infection unless you are on IV antibiotics and get the source under control bad. As an example, colovesicular fistula is a communication between the colon and bladder which often results in bad infections and needs to be surgically repaired. Hope this helps.
Delphia@lemmy.world 7 months ago
Ok but why cant I have a secondary urethra grafted in that runs in my leg down to a nice discreet exit on my ankle so I can take a sneaky wee when Im out and about.
finthechat@kbin.social 7 months ago
You could just tape a garden hose to your dick and run it down a pant leg. Man, I should patent this idea....
Thurkeau@lemmy.world 7 months ago
Then you’d be right back where you started for my purposes, still losing moisture unnecessarily.
HeyThisIsntTheYMCA@lemmy.world 7 months ago
No he’s asking what if humans had cloacas
Thurkeau@lemmy.world 7 months ago
I can totally see that, though what if the body was able to adapt to the new configuration and keep the gut bacteria in its place, but the urine still flowed into the bowels for reprocessing? What else would the large intestines pick up aside from water and maybe salt?
Rin@lemm.ee 7 months ago
There’s not much in urine except water, maybe a little bit of sugar if you’re diabetic. I don’t think this would be a beneficial adaptation. I’m pretty sure that if this was advantageous, it would have been adapted way earlier in our evolution.