The preventive and therapeutic measures for the treatment and prevention of diarrhea recommended in the Programme for the Control of Diarrhoeal Diseases, initiated by the World Health Organization and adopted by the Pan American Health Organization, are based on knowledge of the mechanisms of microorganism-host interaction, the pathophysiological alterations of the gastrointestinal tract and the general metabolic changes that occur during enteric infections.
Therapeutic measures are aimed at preventing or correcting dehydration and the nutritional damage caused by diarrheal diseases, while preventive measures are aimed at reducing the incidence of these diseases. It is considered that, through the widespread application of these measures at all levels of care, a significant reduction in mortality among children under five years of age will be achieved.
Since 1978, oral rehydration therapy has been used successfully in the countries of the Region of the Americas. It has been shown that it can replace intravenous rehydration in 95 to 97% of cases of mild and moderate dehydration, and in certain cases of severe dehydration greater than 10%.
In some countries, this therapy is applied almost exclusively in hospitals and health centers of varying complexity, while in others it has been implemented at all levels of care. Despite these advances, most health personnel do not consider the application of this methodology to represent a substantial change in traditional approaches to treating children with diarrhea.
On the contrary, they believe it is a simple therapy designed either to be applied only in mild cases of dehydration or to prevent it. They also consider it useful only for the treatment of dehydration, giving little importance to the second component of the therapy: maintaining feeding during the acute phase of diarrhea.
This article addresses aspects related to the dietary management of children with diarrhea, with special reference to maintaining feeding during the illness in order to prevent or reduce the nutritional damage it causes.
Diarrhea and Nutrition
The synergistic interaction between infection and nutrition is well known. Infectious diseases produce nutritional damage characterized by acute weight loss and by the physiological and metabolic changes that occur during the infectious process.
Diarrhea causes even greater damage, since the alterations caused by intestinal infection are compounded by the direct loss of nutrients, water and electrolytes, as well as by decreased intake caused by anorexia.
This may be further worsened iatrogenically by fasting imposed on the child, whether because of popular beliefs or, more unfortunately, because of medical practices that prescribe a fasting period of 24 to 48 hours while intravenous rehydration is performed. This fasting period is followed by the slow and progressive reintroduction of food.
In this way, the child may receive hypocaloric diets for 7 to 10 days following acute diarrhea, thereby prolonging the period during which they enter negative nitrogen balance.
During the acute period of the illness, the child is irritable, anorexic and may have fever and vomiting. This causes a decrease in intake that, in some cases, lasts for more than a week. It is known that restriction in calorie consumption during diarrhea ranges from 20 to 60%. Such restriction, which is related to the type and severity of the infection, is greater in cases of diarrhea caused by rotavirus and Shigella and lower in cases of toxigenic cholera-like diarrhea.
Most enteric infections caused by viruses or invasive bacteria produce anatomical and physiological alterations in the intestine, as well as changes in the composition of the intestinal flora, which may cause a decrease in the normal processes of food digestion and absorption.
In almost all cases, these changes are transient and short-lived, appearing during the acute period and early convalescence of the illness, when metabolic alterations occur with increased catabolism that induce a negative nitrogen balance.
However, in cases of rotavirus diarrhea, the decrease in nutrient absorption may be more prolonged. It has been reported that in cases of dysentery caused by shigellosis, protein loss occurs through the direct exudation of serum protein through ulcerations produced in the large intestine.
In cases of cholera-like toxigenic diarrhea, these lesions do not occur and intestinal absorption processes are not altered. However, secretion increases, causing intense diarrhea with acute weight loss, but without preventing the absorption of water, electrolytes and nutrients.
The relationship between diarrhea caused by enterotoxigenic Escherichia coli and nutrient absorption has not yet been well established. It was recently shown that in cases of diarrhea caused by enterotoxigenic E. coli strains producing stable toxin, the decrease in intestinal absorption is greater than in cases of cholera.
The result of these processes is acute weight loss.
