How come things like magnesium can liquify the solids in your intestinal track in a matter of 20 minutes?



… or even other things like food poisoning, when you eat something and get diarrhea 20 minutes later. Someone told me it’s not actually what you just ate coming out, but what’s been sitting there. I can say with certainty that it’s sometimes what I just ate because I’ll see the ingredients I just ate come out! I thought it takes a whole day for food to get into the bottom of your small intestine.

This isn’t a chronic diarrhea problem for me lol the topic just came up and now I’m curious.

In: Biology

If your body thinks its been poisoned, it will try to get rid of the poison. If you’ve inhaled it, it will cough or sneeze. If it’s in your eyes, you’ll cry and blink a lot so the tears can wash it out. If you’ve eaten it, you will vomit and/or poop it out. This circumvents the usual residence time of food in your intestines; your body’s priority is to prevent the poisoning, not to extract nutrients from the food.

Magnesium is different in that it can’t easily be absorbed by the intestines, so the osmotic pressure draws water out of the surrounding blood and into the *colon. This makes your excrement looser and increases its volume in your colon. The increased volume signals to your colon that it needs to empty, which triggers in increasing your urge to poop. If you have anything in there, it’ll come out. If you have nothing in there, you’ll have a watery discharge.

Edit: *colon