Probably a dumb question, but I assume that urination would indicate that ruination would mean that the nutrients that has been absorbed where used and filtered if needed. Intaking nutrients prior to urinating may overwhelm the blood stream then. Correct me if I’m wrong please.
No, it means the bladder is full, and ready to be emptied. Your kidneys make urine, and dump it into your bladder. Your kidneys filter your blood, and remove any toxic metabolites from metabolic processes. They also remove excessive amounts of salts, and water from the blood. The yellow stuff in your urine is urea, which comes from catabolism of protein products.
Quick and simple answer: Shitting is the end of the food processing, pissing is the end of the water processing, Shit is useless parts of food leaving, Piss is useless parts from all around your body leaving. There is nothing between them that changes anything, they work all the time and empty when need emptying, again, shitting to get rid of shit and pissing to get rid of piss when needed.
TL;DR: No.
The production of urine by the kidneys is a continual process of filtering the blood to remove metabolites from various bodily processes. While everything in your urine is made up of molecules that were, at some point, molecules found in something you ate or drank (plus some molecules from what your mother ate/drank before/during pregnancy depending on your age), there could be a very long time between when those molecules were consumed and when they exited as waste.
Bones, for example, are constantly regenerating by adding new calcium from the blood and simultaneously releasing old calcium back into the blood and they turn over roughly every 10 years. So at any given moment, you could be peeing out calcium that was from your meal a few hours ago or peeing out calcium you ate a decade ago. And your current bone density will be impacted by your calcium intake (among several other factors) over man years.
There are a lot of mixed answers with many claiming fact, but I haven’t seen it acknowledged that you are partially correct. The small intestine is responsible for absorbing water and is the last part of digestion. That being said, how the body manages water is well beyond digestion. Therefore, urination doesn’t have a single cause and cannot be used as an indication of digestion.