Drugs for diarrhoea
Antibiotics do not improve diarrhoea Evidence Level A
Andiarrhoeal mixtures and drugs are not useful
Probiotics have variable effectiveness in specific
circumstances
Zinc acetate for 2 weeks reduces duration and
recurrence risks Evidence Level A
Vitamin and mineral supplementation should be given for deficiencies
Dehydration is the main acute risk of acute gastroenteritis. Watery stools develop as a result of a secretion-absorption imbalance of the gut mucosa; however, glucose-linked sodium absorption with secondary water uptake is maintained even in secretory states like cholera. This is the basis of oral rehydration therapy (ORT). Hypotonic fluids with a sodium content of 45 - 65 mmol/l (e.g. Rehidrat, Sorol) allow more rapid rehydration than fluids with a higher sodium content,29 but hypertonic sugar-based drinks with little sodium (e.g. cola and sports drinks) may result in osmotic aggravation. A home-made salt-and-sugar solution (SSS) (half a teaspoon of salt plus 8 teaspoons of sugar per litre of water) is useful, but of unpredictably variable concentration, and is therefore best used in the early stages before dehydration has set in.
Dehydration occurs because fluid loss exceeds fluid intake. In general, signs of dehydration lag behind water loss. The best guide to the risk of developing dehydration is the frequency of watery stools: assuming a deficit of 10 ml/kg of body mass for each watery stool. This amount of fluid should be offered to the child in addition to usual fluid intakes.
Initially, the emphasis is on maintaining fluid intake despite vomiting, offering feeds according to tolerability. Small frequent liquid feeds are better tolerated than large volumes or solids. Feeds should be followed with clear hypotonic fluids such as SSS, or even dilute juices or mildly sweetened tea – as much as the child wants, in small quantities. Commercial rehydration fluids are also suitable. Taste may be an issue in the case of anorexia or vomiting; caregivers may need to be creative in adapting or hiding the taste of rehydration fluids.