The treatment of diarrhoea

Overview

Diarrhoeal diseases are a leading cause of childhood morbidity and mortality in developing countries, and an important cause of malnutrition. In 2003 an estimated 1.87 million children below 5 years died from diarrhoea. Eight out of 10 of these deaths occur in the first two years of life. On average, children below 3 years of age in developing countries experience three episodes of diarrhoea each year. In many countries diarrhoea, including cholera, is also an important cause of morbidity among older children and adults.

Many new microbial causes of diarrhoea have been discovered during the past three decades. Research laboratories can now identify a microbial cause in over three quarters of children presenting at health facilities with diarrhoea. Information about the most important diarrhoea-causing pathogens is given in Annex 1.

Many diarrhoeal deaths are caused by dehydration. An important development has been the discovery that dehydration from acute diarrhoea of any aetiology and at any age, except when it is severe, can be safely and effectively treated in over 90% of cases by the simple method of oral rehydration using a single fluid. Glucose and several salts in a mixture known as Oral Rehydration Salts (ORS) are dissolved in water to form ORS solution (Annex 2). ORS solution is absorbed in the small intestine even during copious diarrhoea, thus replacing the water and electrolytes lost in the faeces. ORS solution and other fluids may also be used as home treatment to prevent dehydration. After 20 years of research, an improved ORS solution has been developed. Called reduced (low) osmolarity ORS solution, this new ORS solution reduces by 33% the need for supplemental IV fluid therapy after initial rehydration when compared to the previous standard WHO ORS solution. The new ORS solution also reduces the incidence of vomiting by 30% and stool volume by 20%. This new reduced (low) osmolarity ORS solution, containing 75 mEq/l of sodium and 75 mmol/l of glucose, is now the ORS formulation officially recommended by WHO and UNICEF. In this revised document, when ORS/ORT is mentioned, it refers to this new reduced (low) osmolarity ORS solution.

Bloody diarrhoea (dysentery) and persistent diarrhoea with malnutrition are also important causes of death. Repeated attacks of diarrhoea contribute to malnutrition, and diarrhoeal diseases are more likely to cause death in children who are malnourished. Research has shown, however, that the adverse effects of diarrhoea on a child's nutritional status can be lessened or prevented by continuing feeding during the illness.

Diarrhoea morbidity is increased in HIV positive children. However, the treatment of diarrhoea for HIV positive children is generally the same as for HIV uninfected children, although lactose and monosaccharide intolerances are more frequently present in these children.

Essential elements in management of the child with diarrhoea are the provision of oral rehydration therapy and continued feeding to all, and the use of antimicrobials only for those with bloody diarrhoea, severe cholera cases, or serious non-intestinal infections. The caretakers of young children should also be taught about feeding and hygiene practices that reduce diarrhoea morbidity.

This manual describes the principles and practices of treating infectious diarrhoea, especially in young children. It is intended for physicians and other senior level health workers. Other publications are available to assist in the training of other health staff, including community health workers1 .

This fourth revision of the manual reflects recent clinical experience and research findings in diarrhoea case management. Compared to earlier versions, it includes revised guidelines on the management of children with acute diarrhoea using the new reduced (low) osmolarity ORS formulation and using zinc supplements, which have been shown to reduce duration and severity of diarrhoeal episodes, and revised guidelines for the management of bloody diarrhoea. Guidelines in the manual are based on the revised WHO chart that are included at the end of this document.