Children with diarrhoea lose both fluid and electrolytes in the stool. Important electrolytes which are lost include sodium, potassium, calcium, magnesium, chloride, phosphate, and bicarbonate. Electrolytes are also lost with excessive vomiting.
Children with diarrhoea lose excessive amounts of fluid and electrolytes in the stool.
An electrolyte imbalance (too much or too little of one or more of the electrolytes) may be caused by dehydration or using an incorrect rehydration fluid. Electrolyte imbalance presents as floppiness (hypotonia), drowsiness or fits.
Children who lose more water than sodium develop hypertonic (hypernatraemic) dehydration. These children are very irritable and may have convulsions. The diagnosis may be missed as the signs of dehydration are less obvious.