Most of the fluid you drink is absorbed into the bloodstream through the small intestine and colon. Normally, only a small amount is lost in the feces. Diarrhea causes excess water loss through the feces.
By the time water has reached the small intestine, it has accumulated more fluid from digestive juices and saliva. Most of this fluid is reabsorbed into the bloodstream from the small intestine. The colon then squeezes out almost all remaining fluid, leaving only about 100-200 mL fluid to be lost in feces.
Diarrhea results when intestinal contents move too quickly through the system, increasing the amount of fluid lost through fecal matter. Persistent diarrhea may lead to dehydration.
“Who touches a boy by the Master's plan Is shaping the course of a future man, Is dealing with one who is living seed And may be a man whom the world will need.” -Anonymous