Acute gastroenteritis is characterized by a rapid onset of diarrhea with or without vomiting, nausea, fever, and abdominal pain.1 Diarrhea is defined as the frequent passage of unformed liquid stools.2 Diarrheas are a leading cause of childhood morbidity and mortality particularly in developing countries. Its attendant nutritional compromise is an important cause of malnutrition. An estimated 1.87 million children below 5 years in 2003 died from diarrhea, 80 percent of which occurred in the first two years of life. It is also estimated that children below three years of age in developing countries annually experience three episodes of diarrhea.3
Many diarrheal deaths are caused by dehydration. The cornerstone of therapy in diarrheal dehydration is the correction of the physiologic disturbances brought about by diarrhea and its attendant metabolic derangements.4 The discovery that dehydration from acute diarrhea of any etiology and at any age, except in severe cases, can be safely and effectively treated in over 90% of cases by oral rehydration therapy (ORT) was considered the medical advance of the 20th century. ORT utilizes physiologic oral rehydration solutions (ORS) that contain the appropriate concentrations of important electrolytes lost in the stools and the carbohydrate substrate for effective sodium absorption. ORS is intended to replace the fluid loss and the stool electrolyte wastage of various causes of diarrheas. Viral diarrheas usually have a stool sodium loss of 40-60 mmol/L while toxigenic diarrhea, like cholera enteritis, can result in stool sodium losses of as much as 120-140 mmol/L.5,6 Along with continued feeding and zinc supplementation, ORS can effectively address most of the physiologic disturbances in diarrhea.3
WHO Physiologic ORS
The original WHO ORS formulation was promoted in 1975 by the WHO and the UNICEF as a single preparation designed for the treatment of diarrhea from various types of diarrhea with varying degrees of electrolyte losses for diverse populations.6 Its initial formulation containing a concentration of 90 mmol sodium/L and 2% glucose with a total osmolarity of 331 mosml/L represented a middle value for the stool sodium losses between cholera enteritis and other causes of diarrhea. Subsequent researches led to the modification of the original formulation and since 2004, the WHO and UNICEF has jointly endorsed the use of physiologic ORS containing a reduced sodium of 50-75 mmol/L and total osmolarity of 210-268 mOsm/L.3, 7 This new WHO ORS is superior to the initial formulation as it reduces vomiting, shortens hospitalization stay, and lessens the need for IV fluids.8 This reduced osmolarity ORS appears to be safe and effective in the treatment of cholera enteritis in children.9
Children with no signs of dehydration need extra fluids and salt to replace their diarrhea losses through the use of fluids containing salt. Suitable fluids containing 3 g/L of salt include ORS solution, salted drinks (salted rice water or a salted yoghurt drink), vegetable or chicken soup with salt. Certain fluids that are potentially dangerous and should therefore be discouraged because of too high sugar content (more than 18 g/L) include drinks sweetened with sugar, commercial carbonated beverages, commercial fruit juices, sports drinks and sweetened tea.10
Sports Drinks are Nonphysiologic
With this current physiologic WHO ORS formulation as the gold standard for effective ORT to prevent and correct diarrheal dehydration, the use of nonphysiologic drinks like sports drinks is not recommended for ORT of acute diarrheas. Sports drinks have a very low sodium concentration of around 20 mmol/L, low potassium of <10 mmol/L and high osmolarity of >330 mOsm/L because of their high carbohydrate concentration of 5-7%. Such a low sodium, low potassium and high osmolar drink can provoke further electrolyte imbalance and osmotic diarrhea. The American Academy of Pediatrics in its clinical practice guideline on acute gastroenteritis likewise discourages the inappropriate use of nonphysiologic solutions like sports drinks to treat children with diarrheas.11
8 Hahn S, Kim Y, Garner P. Reduced osmolarity oral rehydration solution for treating dehydration caused by acute diarrhoea in children. The Cochrane Database of Systematic Reviews 2002, Issue 1. Art. No.: CD002847. DOI: 10.1002/14651858.CD002847.
9 Murphy C, Hahn S, Volmink J. Reduced osmolarity oral rehydration solution for treating cholera. The Cochrane Database Syst Rev 2004, Issue 4. Art. No.: CD003754.pub2. DOI: 10.1002/14651858.CD003754.pub2.