<P> If there is blood visible in the stools, it is also known as dysentery . The blood is a trace of an invasion of bowel tissue . Dysentery is a symptom of, among others, Shigella, Entamoeba histolytica, and Salmonella . </P> <P> Diarrheal disease may have a negative impact on both physical fitness and mental development . "Early childhood malnutrition resulting from any cause reduces physical fitness and work productivity in adults," and diarrhea is a primary cause of childhood malnutrition . Further, evidence suggests that diarrheal disease has significant impacts on mental development and health; it has been shown that, even when controlling for helminth infection and early breastfeeding, children who had experienced severe diarrhea had significantly lower scores on a series of tests of intelligence . </P> <P> Diarrhea can cause electrolyte imbalances, renal impairment, dehydration, and defective immune system responses . When oral drugs are administered, the efficiency of the drug is to produce a therapeutic effect and the lack of this effect may be due to the medication travelling too quickly through the digestive system, limiting the time that it can be absorbed . Clinicians try to treat the diarrheas by reducing the dosage of medication, changing the dosing schedule, discontinuation of the drug, and rehydration . The interventions to control the diarrhea are not often effective . Diarrhea can have a profound effect on the quality of life because fecal incontinence is one of the leading factors for placing older adults in long term care facilities (nursing homes). </P> <P> Acute diarrhea is most commonly due to viral gastroenteritis with rotavirus, which accounts for 40% of cases in children under five . In travelers, however, bacterial infections predominate . Various toxins such as mushroom poisoning and drugs can also cause acute diarrhea . </P>

Where does the fluid in diarrhea come from