Vomiting and Diarrhea: precious essential defense mechanism
When the body comes into contact with a toxic substance or poison through the gastrointestinal system, it does the most logical thing it can do: get away as fast as it can from the toxic substance through vomiting and diarrhea.
Vomiting is an extremely direct way; whatever is in the stomach that the body perceives as toxic is directly rejected. The body is so sophisticated that vomiting can be initiated even from the duodenum, the first section of the intestines.
In fact, it is able to reverse the direction of peristalsis motion (the movements that “push” the contents toward the natural exit), bringing it to the stomach and then expelling it.
When the poison gets further into the intestines, the body does another entirely logical and functional thing: it increases the speed of peristalsis in order to expel as soon as possible.
Thereby, the intestinal contents will fortunately only be partly absorbed, becoming semi-liquid or liquid at the rectum and generating diarrhea.
In these ways, the body prevents absorption of toxins or poisons ingested via the stomach.
It would seem from this that vomiting and diarrhea are indeed essential defense mechanisms.