Diarrhea is an increase in stool frequency and fluidity that is abnormal and can be caused by infectious agents transmitted through the fecal-oral route. It is most common in children under two years old and in developing countries where breastfeeding and hygiene practices increase risk. Diarrhea can be acute, persistent, or dysentery. The pathophysiology involves disruption of the normal absorption and secretion of water and electrolytes in the intestines by mechanisms like bacterial toxins or poorly absorbed solutes causing an osmotic effect.