In cases of prolonged diarrhea or frequent episodes of intestinal infection, it is observed that, in addition to weight loss, growth may stop, which can lead to nutritional dwarfism; that is, a deficit in height in relation to chronological age. In these cases, severe morphological and physiological alterations have been documented, generally associated with chronic malnutrition processes. Research on the epidemiology of malnutrition has shown that diarrhea plays a very important role in the etiology of both acute and chronic malnutrition. Maintaining feeding during the illness and shortening its duration is one way to reduce or prevent the nutritional damage it causes.
Feeding During Diarrhea
The practice of partial or total fasting in the treatment of diarrhea is based on the belief that the rapid transit of intestinal contents, the reduction in enzymatic activity of intestinal cells, and the damage caused by microorganisms to the intestinal mucosa affect food absorption during the illness.
It is now recognized that these alterations exist mainly in severe diarrheal processes. In general, these processes correspond to chronic cases associated with malnutrition and represent less than 5% of diarrheal episodes. On the other hand, most diarrheal diseases are acute in nature and resolve or improve within an average period of seven days. Therefore, it is unnecessary to establish dietary restrictions in children with uncomplicated acute diarrhea.
Basis for Promoting Feeding in Children with Diarrhea
Recent research on the absorption and utilization of food in patients with diarrhea has shown that:
· Infectious diarrheas cause a temporary decrease in disaccharidase activity, which may interfere with the digestion and absorption of lactose, but not of other disaccharides. This alteration occurs mainly in diarrhea caused by viruses or invasive enterobacteria, while in toxigenic diarrhea the damage is less significant.
· No true relationship has been demonstrated between the duration of diarrhea and the volume and type of food consumed, the volume and frequency of bowel movements, or the speed of intestinal transit.
· Although absorption of nitrogen, carbohydrates and fats is reduced during most diarrheal episodes, a substantial amount of nutrients is always absorbed, enough to achieve a positive balance.
It has also been shown that reducing intake may worsen diarrhea:
· A fasting period of 3 to 5 days worsens the alterations caused by intestinal infection, since the absence of food in the intestinal lumen causes intestinal cells to further reduce enzyme production because they lack the stimulus provided by food. Consequently, sugar absorption decreases. When sugars remain in the intestinal lumen, they may worsen diarrhea by drawing water into the intestine because of their high osmotic activity. In other words, fasting and diarrhea may have a synergistic effect, increasing intestinal malabsorption and thus prolonging diarrhea, with a high risk of worsening nutritional status. It may also cause hypernatremic dehydration due to this type of watery diarrhea, which contains a high amount of water and little sodium.
· A low-calorie diet for 10 days causes a 42% reduction in the respiratory response to hypoxia and a 25% reduction in basal metabolic rate.
It has also been shown that the presence of food in the intestinal lumen facilitates the recovery and maturation of intestinal cells:
· Organic substrates, such as glucose or glycine, facilitate the absorption of sodium and water.
· Both carbohydrates and proteins in the intestinal lumen stimulate the production of intestinal digestive enzymes and favor cell proliferation and maturation. It appears that each type of substrate interacts with different sodium transporters; consequently, when two or more substrates are present in the intestine, an additive effect is observed in the absorption of sodium and water.
· One substrate, such as glucose, may reverse intestinal secretion and the clinical symptoms of malabsorption induced by another substrate, such as lactose.
· Dietary carbohydrates induce the production of intestinal enzymes and therefore have a protective, not harmful, effect on the intestinal mucosa. Thus, a mixed carbohydrate diet could prevent disaccharidase depletion during diarrhea.
· Similarly, the presence of whole cow’s milk in the intestine, administered in small quantities, will induce lactase production, allowing the milk to be tolerated when given in larger quantities two or three days later.
According to this information, it may be concluded that, despite the temporary decrease in food absorption, feeding should continue during diarrhea, since significant nutrient absorption always occurs, even during the acute phase of the illness. In addition, it has been shown that diarrhea does not worsen when children receive food. In this way, feeding during the illness can compensate for the nutrient losses caused by diarrhea, thereby helping to prevent or reduce the nutritional damage produced by enteric infections.
