Diarrhoead in infants usually has an infective aetiology.
Despite this, there are some important non-infective causes.
infectious diarrhoea in children
Infectious diarrhoea in children is a very common problem, most of which is viral, principally rotavirus.
The important features of management are:
recognition of more serious causes of diarrhoea, for example, if there is blood in the stool - ie the possibility of intussusception
appropriate treatment is usually conservative, antibiotics and gut motility inhibitors are rarely required
adequate oral rehydration at an early stage
More than 90% of infectious diarrhoea in infants has a viral aetiology - in fact 90% is caused by rotavirus, a virus which can cause infections of both the GIT and URT. Other viruses include Echo and Enteroviruses.
A bacterial aetiology is suggested by high pyrexia and bloody diarrhoea. This is principally Enteropathic E. coli, although Shigella, Salmonella and Campylobacter should be borne in mind. World-wide, cholera must be considered, especially currently in South America.
Chronic infections might suggest protozoans, for example Giardia lamblia. This causes three or four episodes of foul smelling diarrhoea a day, and a diagnosis is made on the basis of cysts found in the stool.
Environmental factors include:
poverty and overcrowding, in the absence of clean water supply, proper sewerage disposal and appropriate personal hygiene are important internationally
malnutrition is a strong contributory factor
bottle feeding, with incorrect sterilisation
The highest risk groups are children under six months old in the developed, or infants bottle fed or between weaning and the second year in the developing world.
pathophysiology of infective diarrhoea
Infective organisms are able to cause diarrhoea in a variety of ways:
mucosal damage caused by direct attack
toxin production after ingestion
toxin production before ingestion
The diarrhoea itself can be:
secretory, where deranged membrane transport results in decreased electrolyte absorption and thus decreased water absorption
decreased absorption, itself a result of mucosal damage, osmosis, or increased gut motility
treatment of childhood diarrhoea
Medicinal intervention in diarrhoea is not often recommended, since antibiotic treatment in itself may lead to pseudomembranous colitis.
In cases of Giardia lamblia and of amoebic dysentry metronidazole is given.
In treatment of diarrhoea, the most important factor is to maintain hydration, thus oral rehydration therapy.
Perhaps an important prophylactic treatment of diarrhoea is to encourage breast feeding - maternal IgA, lactoferrin, neutrophils and macrophages all contribute to protection from diarrhoea.
non-infectious diarrhoea in children
Non infectious causes of diarrhoea would tend to cause a more chronic diarrhoea. Causes include:
cow's milk intolerance
ulcerative colitis and Crohn's disease
acrodermatitis enteropathica - zinc deficiency
diarrhoea and vomiting in infants and children
The possible causes of diarrhoea and vomiting in infants and children can be classified as: