Gastrointestinal infections, particularly in the under-5s, can place a huge burden on health services. Edward Purssell looks at the issue from a nutritional perspective 

Edward Purssell, BSc, MSc, PhD, RGN, RSCN, Senior Lecturer, Department of Primary Care and Child Health, Florence Nightingale School of Nursing and Midwifery, King's College London ttgastro1   

Infections are common in young children because of their limited immunological development and reliance on others to maintain their hygiene and nutrition. Although serious infection in developed countries is rare and so mortality is low, gastrointestinal infections impose a significant burden on health services. This is largely due to frequency of occurrence; it is estimated that a child under five will have two to three episodes of gastroenteritis per year (Lorgelly, Joshi, Iturriza Gómara et al, 2008).

Q1 What are the main causes of gastrointestinal infection?  

The National Institute for Health and Clinical Excellence (NICE) defines diarrhoea as the passage of liquid or watery stools, often accompanied by an increase in frequency and volume; and vomiting as the forceful ejection of stomach contents up to and out of the mouth (NIHCE, 2009). It is particularly important to differentiate vomiting from regurgitation (bringing up milk effortlessly, sometimes known as "posseting"), and gastro-oesophageal reflux. The most common causes of diarrhoea and vomiting are viruses, in particular rotavirus, but also norovirus, sapovirus, astrovirus and adenovirus. Some bacteria such as Campylobacter and Salmonella, and more rarely some protozoa such as Cryptosporidium and Giardia, may also cause disease (Sharland, 2011).

Q2 Are there any specific risk-factors for gastrointestinal infection?  

In the United Kingdom, contributing factors to diarrhoeal infection may be associated with belonging to poorer families where the main wage earner is semi-skilled or unskilled, overcrowding, inadequate sterilisation of feeding equipment, and contact with a person with diarrhoea (Quigley, Cumberland, Cowden et al, 2006). Education, particularly around good hygiene practices, might therefore best be targeted at people with these characteristics.

Q3 Does the incidence of gastrointestinal infection vary throughout the year?  

Most viral infections have a seasonal peak. In the case of gastrointestinal viruses, and rotavirus in particular, this occurs in the spring. For bacterial infections such as Campylobacter and Salmonella the peak tends to be in the summer (Morgan, Adlard, Carroll et al, 2010). Where there is a common source for the infection, for example, a nursery, this will depend on local factors.

Q4 Do children with gastrointestinal infection need antibiotics?

Most cases of gastrointestinal infection are self limiting and do not require treatment beyond increasing the intake of fluids containing appropriate levels of electrolytes. However, dysentery, which is indicated by the presence of blood and mucous in the stool, is an indication of an invasive infection that may require treatment, and Escherichia coli O157:H7 may lead to haemolytic uraemic syndrome (NIHCE, 2009). Antibiotics are not effective against viruses which cause most cases, and parents who ask for antibiotics should be told that not only are they not effective, but overuse may lead to antibiotic resistance and actually increase the risk of infection by disrupting the child's normal bacteria.

Q5 What other conditions may present with diarrhoea and vomiting? Other conditions that may also present in this way include infections such as pneumonia, urinary tract infections, meningitis and otitis media; other gastrointestinal conditions such as ulcerative colitis, Crohn's or coeliac disease; and surgical conditions such as bowel obstruction or intussusception (where the bowel folds into itself, like a telescope). As well as being a symptom of disease, diarrhoea and vomiting may also result from taking some medicines, particularly antibiotics. Signs and symptoms that may suggest other diagnoses in a baby include a temperature of 38°C, shortness of breath or tachypnoea (abnormally rapid breathing rate), altered consciousness, neck stiffness, bulging fontanelle, non-blanching rash, blood or mucous in the stool, bile stained vomit, severe or localised abdominal pain, or abdominal distension (NIHCE, 2009).

Q6 What are the benefits of breastfeeding in the prevention of infection?  

The UK Millennium Cohort Study suggests that exclusive breastfeeding has a protective effect against diarrhoea, and could prevent around 53 per cent of hospitalisations (Morgan, Adlard, Carroll et al, 2010); partial breastfeeding has less effect, but could still prevent around 31 per cent (Quigley, Kelly, Sacher et al, 2007). When a broader group of children were studied, that is those attending their local GP, similar findings resulted, but in addition researchers found these effects were stronger in more deprived areas and more crowded households (Quigley, Cumberland, Cowden et al, 2006).

Q7 What are the beneficial constituents of breast milk? Breast milk has a number of protective effects which result from the presence of proteins, such as antibodies and lysozyme, which directly damage bacterial cells and carbohydrates, which act as prebiotics and encourage a balanced gastrointestinal bacterial flora. Additionally there are immune modulating factors such as cytokines, which stimulate the immune response; and nutrients that encourage normal growth and development. Collectively these have direct antimicrobial activity, stimulate immune function and development, modulate how the immune response functions, have anti-inflammatory effects and enhance growth and development (Lawrence, Pane, 2007).

Q8 What are the benefits of pre/probiotics in preventing infection?  

Probiotics are substances that contain microorganisms in sufficient amounts to alter the flora of the host, while prebiotics are non-digestible foods that stimulate the growth of this flora. Breast milk contains a number of prebiotics, while close contact between mother and baby encourages a normal flora. Some formula milks contain prebiotics, such as fructooligosaccharides (FOS) and galacto-oligosaccharides (GOS), and there is some evidence that their inclusion in formula milk might lead to a reduction in gastrointestinal and some other infections (Bruzzese, Volpicelli, Squeglia et al, 2009). Because probiotics are live bacterial products, they should not be given routinely in formula milk until there is evidence of their safety and benefit (Scientific Advisory Committee on Nutrition, 2009).

Q9 What hygiene advice should be given to parents?  

Before preparing formula feeds, parents should wash their hands and sterilise all equipment (Department of Health, 2011) to reduce the risk of infection from contaminated equipment. Water should be boiled and left to cool to no less than 70°C (Food Standards Agency, Department of Health, 2005). Fresh feeds should be made up as required and not stored. Parents and children should also wash their hands with soap in warm running water after going to the toilet and changing nappies and before preparing, serving or eating food, taking care to dry them afterwards. Towels should not be shared with the infected child, who should have their own. Children should not return to their childcare facility until at least 48 hours after the last episode of diarrhoea or vomiting (NIHCE, 2009). More details on isolation for infectious diseases is available from the Health Protection Agency (Health Protection Agency, 2010).

Q10 How soon should normal feeding be resumed after suffering from gastroenteritis?  

Normal breast or formula feeding should be continued as soon as possible. Although some children may show signs of lactose or cow's milk intolerance following gastroenteritis, this is a temporary phenomenon, and lactose-free or soya milks are not required. Giving diluted milk is not recommended either as it provides no appreciable benefit and may reduce the nutritional value of the milk or lead to electrolyte imbalance. Similarly the use of flat carbonated drinks and fruit juice is not advised (NIHCE, 2009).


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2. National Institute for Health and Clinical Excellence. Diarrhoea and vomiting caused by gastroenteritis: diagnosis, assessment and management in children younger than 5 years. London: National Collaborating Centre for Women's and Children's Health, 2009
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5. Morgan C, Adlard N, Carroll S et al. Burden on UK secondary care of rotavirus disease and seasonal infections in children. Curr Med Res Opin 2010; 26(10): 2449-2455
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8. Bruzzese E, Volpicelli M, Squeglia V et al. A formula containing galacto- and fructo-oligosaccharides prevents intestinal and extraintestinal infections: an observational study. Clin Nutr 2009; 28(2): 156-161
9. Scientific Advisory Committee on Nutrition (2009). Subgroup on Maternal and Child Nutrition (SMCN). SCF report on the Composition of Infant Formula [Accessed Feb 2012]
10. Department of Health (2011). Guide to bottle feeding http://www. digitalasset/dh_124526.pdf [Accessed Feb 2012]
11. Food Standards Agency, Department of Health (2005). Guidance for health professionals on safe preparation, storage and handling of powdered infant formula [Accessed Feb 2012]
12. Health Protection Agency (2010). Guidance on infection control in schools and other childcare settings HPAwebFile/HPAweb_C/1194947358374 [Accessed Feb 2012]

This article is supported by an educational grant from Aptamil. It represents the educational views of the author and has been independently peer reviewed by JFHC. For more Information please see
The information was correct at the time of publication (Jan/Feb 2012). The next Topic in 10 on weaning the child with cow's milk protein allergy will be published in the March/April issue of JFHC.