Concerning dehydration, it is, perhaps, the main cause of diarrhea in many cases. When the body lacks sufficient amount of water, it cannot function properly. When the person experiences a liquid stool, he or she loses a lot of water. The lack of water may result in other severe diseases and disorders. If you feel exhausted, sleepy, dizzy, and thirsty, mind that it might be the symptoms of dehydration and further diarrhea. Also, pay attention to such signs as dry mucous membranes or rapid heart rate.