How does your stomach determine when to throw your food back up? (Like for food poisoning or something) and how come it’ll digest the food but then you have diarrhea instead? If it was bad, shouldn’t you have thrown it up before it got to the intestines?
In: Biology
Commenting for the diarrhea bit:
Diahrrea is when your body throws up out your butt. This is why it’s mostly water. If your body detects an irritant or some other pathogen it will signal to have your body fill your intestines with water, flushing out whatevers inside. This is why diahrrea causes dehydration. Your body uses a large quantity of water to flush your guts out, so it doesnt have time to be absorbed by your intestines.
For substances that are perceived as acutely toxic to the stomach, you will throw up immediately (e.g. syrup of ipecac will irritate the gastric mucosa). For substances that trigger the CTZ (described in another post), they will induce vomiting a little bit later because the substance needs to enter the bloodstream first and cross the blood brain barrier.
For the remainder of “things that make you sick,” – which is largely limited to infections – they will often produce a ‘toxin’ of sorts (e.g. C. diff) which only is released once the substance makes its way into the small bowel/colon (remember, food doesn’t sit in your stomach for very long. Very little absorption happens there). Bacteria that aren’t killed off by the stomach acid will multiply rapidly in your GI tract. So by the time the bacteria/virus/toxins start to cause their damage, they are well in their way into the small bowels. You can’t purge your bowels north, so you purge them south.
u/jiggity_gee had the best ELI5 answer for this
So your bowels are like a long train track and your food is like a set of cars on the track. Transit time between Point A, your mouth, and Point B, the chute, is a bit flexible but normally operates on a regularly scheduled basis.
When you eat, you put cars on the track and send them to Point B. As these cars go to Point B, they lose passengers (nutrients) at various points in the thin tunnel portion (small intestine). The journey isnt complete and the journey has already altered the shape of the car pretty significantly giving a rusty color. Once in the larger portion of the tunnel, the cars are checked for stray passengers and are hosed down a bit so that transition out of Point B isn’t so bad. Sometimes, the train cars park juuust outside the gates of Point B so they can exit at the best time for the operator (toilet).
Now, all of this goes fucking nuts when you load a bad set of train cars at Point A. The track sensors located everywhere along the track, detect this alien set of cars and sends a distress call to the Supervisor (your brain). The Supervisor wants to handle the situation without having to phone the Manager (your consciousness) about the craziness on the tracks and also wants to make sure you never know it was on the tracks. It has to make a choice now: send it back to Point A violently and somewhat painfully risking tearing the tracks, or send it to Point B as fast as fuck? Depending on where it’s located on the track, it’ll choose the best route.
Let’s use the destination Point B. The Supervisor hits the panic button and puts all the train cars that are on the track (in your body) on overdrive. The tunnels are flooded with water and lubricant to speed all the cars up and get them the hell out of there as quickly as possible. Cars collide with each other, and previously well formed cars are just flooded with water and lubricant that they are just a soggy, shadowy reminder of their former glory state.
The Media (pain) hears about the car collisions immediately begins filming live the high speed, flooded train cars out of control. They want to knos how an alien set of train cars were put on the tracks and they want someone to pay for such carelessness. The Manager is just watching the horror unfold on Live TV but cannot do anything to stop it, because the Supervisor was deaf and he had not installed a means of communicating with him after hours in the office.
I hope this answers your question.
TL;DR when you get diarrhea, everything gets pushed out, one way or another. There are no passing lanes.
Source: medical student
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