The following recommendations provide a framework for making decisions. In all cases clinical judgement is needed — if in doubt, use caution or seek advice.

Ensure alternative diagnoses have been considered (see Differential diagnosis).

Document the frequency and consistency of stools, frequency of vomiting, and whether blood or mucus are present in the stool.

Assess possible sources of infection:

Recent contact with someone with acute diarrhoea and/or vomiting.

Exposure to a possible source of enteric infection (for example eating out).

Recent travel abroad.

Check for indicators of dehydration and shock (see NICE criteria for dehydration - remote assessment).

Arrange emergency transfer to hospital if:

Features of shock are described by the parent or carer.

The child has features that might suggest an alternative life-threatening diagnosis (for example the child seems to be very ill, has a non-blanching rash, or has severe breathing difficulty).

Arrange for a face-to-face assessment (this will usually be on the same day, but use clinical judgement) if:

Symptoms suggest an alternative, serious diagnosis (see Differential diagnosis).

The child has a single acute episode of bloody diarrhoea.

Symptoms suggest the child is dehydrated (see NICE criteria for dehydration - remote assessment).

Risk factors are present which indicate an increased risk of dehydration:

Infants younger than 1 year of age, and especially if younger than 6 months.

Infants who were of low birthweight.

Infants who have stopped breastfeeding during their illness.

Children who have passed six or more diarrhoeal stools in the past 24 hours.

Children who have vomited three times or more in the past 24 hours.

The child's social circumstances make assessment over the telephone unreliable.

If the child is being managed at home with telephone advice:

Advise continued breastfeeding and other milk feeds.

Encourage fluid intake (but discourage fruit juices and carbonated drinks).

Advise parents, carers, and children that:

Washing hands thoroughly with soap (liquid if possible) in warm running water and careful drying is the best way to prevent the spread of gastroenteritis.

A flush toilet should be used, if possible. If a potty must be used, it should be handled with gloves, the contents disposed of into the toilet, and then washed with hot water and detergent and allowed to dry.

Hands should be washed after going to the toilet and changing nappies, and before preparing, serving, or eating food.

Toilet seats, flush handles, wash-hand basin taps, surfaces, and toilet door handles should be cleaned at least daily with hot water and detergent. Also use disinfectant to clean toilets if available. Use a disposable cloth or one dedicated for toilet use.

Towels and flannels used by infected children should not be shared.

Soiled clothing and bed linen should be washed separately from other clothes at the highest temperature they will tolerate (for example 60°C or higher for linen) after removal of excess faecal matter into the toilet. Soaking in disinfectant is not necessary. Do not fill the machine more than half-full to allow for adequate washing and rinsing.

Children should not attend any school or other childcare facility while they have diarrhoea or vomiting.

Children should not go back to school or other childcare facility until at least 48 hours after the last episode of diarrhoea or vomiting. Public Health authorities will advise if a pathogen is isolated from a child's stool sample (for example Salmonella, Escherichia coli O157): longer periods of exclusion are required in some circumstances.

If cryptosporidiosis is suspected or confirmed, children should not enter swimming pools for 2 weeks after the last episode of diarrhoea.

If the child is being managed at home with telephone advice, reassure the parents or carers that:

The usual duration of diarrhoea is 5–7 days, and in most children it stops within 2 weeks.

The usual duration of vomiting is 1 or 2 days, and in most children it stops within 3 days.

They should seek advice from a healthcare professional if their child's symptoms do not resolve within these time frames.

Provide a 'safety net', advising the parents or carers when review is necessary (for example if symptoms of dehydration develop, or the child has persistent vomiting), and how to access further medical help.

Advise the parents or carers to seek immediate medical help if red flag symptoms are identified (for example the child appears unwell or is deteriorating, or is irritable, lethargic, or less responsive).

Consider alternative diagnoses.

Document the frequency and consistency of stools, frequency of vomiting, and whether blood or mucus are present in the stool.

Assess possible sources of infection:

Recent contact with someone with acute diarrhoea and/or vomiting.

Exposure to a possible source of enteric infection (for example eating out).

Recent travel abroad.

Assess for dehydration and shock (see NICE criteria for dehydration - face-to-face assessment).

Arrange emergency transfer to secondary care for children with symptoms or signs suggesting shock (see NICE criteria for dehydration - face-to-face assessment).

Consider further assessment in secondary care in the following circumstances:

Signs consistent with dehydration.

Altered responsiveness, for example, irritable or lethargic.

A single acute episode of bloody diarrhoea.

Young age (less than 6 months of age or less than 8 kg body weight).

History of premature birth, chronic medical conditions (for example severe cardiac or renal disease), or concurrent illness.

Fever 38°C or more for infants younger than 3 months of age, or more than 39°C for children 3–36 months of age.

High output diarrhoea including frequent and substantial volumes.

Persistent vomiting or persistent fever.

Suboptimal response to oral rehydration therapy.

No improvement in 48 hours, or overall condition that is worsening.

Decide whether monitoring the response to rehydration therapy can be carried out safely in the home setting and if so under what level of supervision (for example general practitioner, community children's nurse). If there are concerns about the parent's ability to monitor their child's condition and to provide appropriate care, consider admission to hospital.

When to request a stool sample

Perform stool microbiological investigations if:

There is blood and/or mucus in the stool.

The child is immunocompromised.

Consider performing stool microbiological investigations if:

The child has recently been abroad to anywhere other than Western Europe, North America, Australia or New Zealand, or

The diarrhoea has not improved by day 7, or

There is uncertainty about the diagnosis of gastroenteritis.

How to send a stool sample to the laboratory

Send a single specimen (1 mL, or a pea-sized sample, is the minimum needed for routine investigation) for stool culture and sensitivity.

If the child has recently travelled abroad to anywhere other than Western Europe, North America, Australia or New Zealand, also request tests for ova, cysts, and parasites.

If diarrhoea is recurrent, and parasitic infection is suspected, send three specimens (5 mL each) 2–3 days apart.

Ensure the following details are stated on the request form:

Clinical features (for example systemic illness, fever, bloody stool, abdominal pain; and onset, duration, and recurrence of symptoms).

History of immunosuppression.

Food intake (for example barbecue, restaurant, types of food eaten).

Recent foreign travel (state the country visited).

Recent antibiotic or proton pump inhibitor treatment, or recent hospital admission.

Exposure to untreated water.

Contact with other affected individuals or outbreaks.

For more information on how to advise parents to collect a stool sample, see Collection of stool samples.

In children with gastroenteritis, but without clinical dehydration, advise the parents to:

Continue with the usual feeds, including breastfeeding and other milk feeds.

Encourage fluid intake.

Discourage the drinking of fruit juices and carbonated drinks.

Offer oral rehydration salt (ORS) solution as supplemental fluid to those at increased risk of dehydration.

In children with clinical symptoms or signs of dehydration who can be managed at home, advise the parents to:

Use ORS solution to rehydrate:

For children 5 years of age or younger: give 50 mL/kg body weight for fluid deficit replacement over 4 hours, as well as maintenance volume of ORS solution (breastfeeding can continue, but do not routinely give oral fluids other than ORS solution). See Additional information for an example of how to calculate a child's maintenance fluid volume requirement.

For children older than 5 years of age: give 200 mL ORS solution after each loose stool (in addition to the child's normal fluid intake).

Give the ORS solution frequently and in small amounts.

Consider supplementation with the child's usual fluids if they refuse to take sufficient quantities of ORS solution and do not have red flag symptoms and signs (child appears unwell or is deteriorating, altered responsiveness, sunken eyes, tachycardia, tachypnoea, decreased skin turgor).

Avoid giving solid food.

Monitor the response to oral rehydration therapy by regular clinical assessment.

Seek urgent medical advice if the child is unable to drink, or vomits persistently.

After rehydration, advise the parents to:

Encourage the child to drink plenty of their usual fluids, including milk feeds if these were stopped.

Avoid giving the child fruit juices and carbonated drinks until the diarrhoea has stopped.

Reintroduce the child's usual diet.

Give children at increased risk of dehydration recurring 5 mL of ORS solution per kilogram body weight after each large watery stool.

For more information on which children are at increased risk of dehydration, see Additional information.

Advise parents, carers, and children that:

Washing hands thoroughly with soap (liquid if possible) in warm running water and careful drying is the best way to prevent the spread of gastroenteritis.

A flush toilet should be used, if possible. If a potty must be used, it should be handled with gloves, the contents disposed of into the toilet, and then washed with hot water and detergent and allowed to dry.

Hands should be washed after going to the toilet and changing nappies, and before preparing, serving, or eating food.

Toilet seats, flush handles, wash-hand basin taps, surfaces, and toilet door handles should be cleaned at least daily with hot water and detergent. Also use disinfectant to clean toilets if available. Use a disposable cloth or one dedicated for toilet use.

Towels and flannels used by infected children should not be shared.

Soiled clothing and bed linen should be washed separately from other clothes at the highest temperature they will tolerate (for example 60°C or higher for linen) after removal of excess faecal matter into the toilet. Soaking in disinfectant is not necessary. Do not fill the machine more than half-full to allow for adequate washing and rinsing.

Children should not attend any school or other childcare facility while they have diarrhoea or vomiting.

Children should not go back to school or other childcare facility until at least 48 hours after the last episode of diarrhoea or vomiting. Public Health authorities will advise if a pathogen is isolated from a child's stool sample (for example Salmonella, Escherichia coli O157): longer periods of exclusion are required in some circumstances.

If cryptosporidiosis is suspected or confirmed, children should not enter swimming pools for 2 weeks after the last episode of diarrhoea.

Antidiarrhoeal medications are not recommended for children with gastroenteritis.

Anti-emetics are not recommended for children with vomiting associated with gastroenteritis.

Do not routinely give antibiotics to children with gastroenteritis.

Seek specialist advice regarding antibiotic treatment when:

The child has recently been abroad.

Stool culture reveals a causative organism.

Following specialist advice, antibiotics should be considered for those children:

With suspected or confirmed septicaemia.

With extra-intestinal spread of bacterial infection.

Who are younger than 6 months of age, with Salmonella gastroenteritis.

Who are malnourished or immunocompromised, with Salmonella gastroenteritis.

With Clostridium difficile-associated pseudomembranous enterocolitis, giardiasis, dysenteric shigellosis, dysenteric amoebiasis, or cholera.

Probiotics are not recommended for the management of children with gastroenteritis.

Seek specialist advice regarding antibiotic treatment when stool culture reveals a causative organism.

Provide information to parents and carers.

A range of information sheets for specific causative organisms can be found at www.gutfeelings.org.uk, including:

Campylobacter (pdf)

Cryptosporidium (pdf)

Verocytotoxin-producing Escherichia coli (VTEC) O157 (pdf)

Giardia (pdf)

Salmonella (pdf)

Shigella (pdf)

Reassure the parents or carers that:

The usual duration of diarrhoea is 5–7 days, and in most children it stops within 2 weeks.

The usual duration of vomiting is 1 or 2 days, and in most children it stops within 3 days.

They should seek advice from a healthcare professional if their child's symptoms do not resolve within these time frames.

Provide a 'safety net', advising the parents or carers when review is necessary (for example if symptoms of dehydration develop, or the child has persistent vomiting), and how to access further medical help.

Advise the parents or carers to seek immediate medical help if red flag features are identified (for example the child appears unwell or is deteriorating, or is irritable, lethargic, or less responsive).

Notify the Local Authority Proper Officer (in England and Wales, the local Consultant in Communicable Disease Control) if a case of any of the following is suspected:

Cholera.

Bloody diarrhoea presumed to be due to gastroenteritis.

Food poisoning (organisms that can be implicated in food poisoning include Campylobacter, Escherichia coli O157:H7, Salmonella, Shigella, Giardia, Yersinia enterolytica, Entamoeba histolytica, and norovirus).

Haemolytic uraemic syndrome (HUS).

Complete an official Formal Notification Certificate (from a pad supplied locally) immediately on diagnosis of a suspected notifiable disease and return it to where the pad was obtained within 3 days (this could be the Local Authority, Primary Care Trust, or Health Protection Unit).

If urgent notification is needed (such as for suspected cholera, infectious bloody diarrhoea, haemolytic uraemic syndrome, clusters or outbreaks of food poisoning) telephone the local Health Protection Unit with the details. A Formal Notification Certificate must still be sent within 3 days.

Notify and act on the advice of the public health authorities if an outbreak of gastroenteritis is suspected.

Contact details for Health Protection Units in England can be found through the Local and Regional Services page on the Health Protection Agency website www.hpa.org.uk and for health protection teams for Wales on the National Public Health Service for Wales website www.wales.nhs.uk.

The full list of notifiable diseases can be found on the Health Protection Agency website at www.hpa.org.uk.

Assess the severity of the illness. Ask about:

Frequency and consistency of stools.

The presence of blood in stools.

Frequency of vomiting.

Ability to eat and drink.

Perform an appropriate examination.

Check temperature, blood pressure, and heart and and respiratory rates.

Assess for abdominal tenderness.

Assess for features of dehydration.

Investigate potential causes or contributing factors by asking about:

Recent contact with someone with acute diarrhoea and/or vomiting.

Exposure to a known source of enteric infection (possibly contaminated water or food).

Recent travel abroad.

Recent antibiotics or hospital admission within the last 8 weeks — suspect infection with Clostridium difficile.

Use of proton pump inhibitors (reduction in stomach acid reduces resistance to infective organisms).

Assess personal risk factors:

Age — elderly people are at greater risk of serious dehydration and complications.

Pregnant women are at greater risk of dehydration and complications, for example following Salmonella infection.

Those who are immunocompromised or have co-existing medical conditions (for example renal impairment, inflammatory bowel disease, diabetes mellitus, connective tissue disorders) are at greater risk of more severe disease and complications.

Review medications — certain medications may be affected by severe diarrhoea (for example warfarin, anticonvulsants, and the oral contraceptive pill), or can exacerbate dehydration and renal failure (for example diuretics, angiotensin-converting enzyme inhibitors).

Arrange emergency admission to hospital if:

The person is vomiting and unable to retain oral fluids.

They have features of shock or severe dehydration.

Other factors influencing admission (clinical judgement should be used) include:

Recent foreign travel.

Older age (people 60 years of age or older are more at risk of complications).

Home circumstances and level of support.

Fever.

Bloody diarrhoea.

Abdominal pain and tenderness.

Faecal incontinence.

Diarrhoea lasting more than 10 days.

Increased risk of poor outcome, for example:

Coexisting medical conditions — immunodeficiency, lack of stomach acid, inflammatory bowel disease, valvular heart disease, diabetes mellitus, renal impairment, rheumatoid disease, systemic lupus erythematosus.

Drugs — immunosuppressants or systemic steroids, proton pump inhibitors, H₂-receptor antagonists, simple antacids, angiotensin-converting enzyme inhibitors, diuretics.

When to send a stool sample for culture

Stool cultures are usually not necessary for most adults who present with acute, watery diarrhoea.

Send a stool specimen if:

The person is systemically unwell.

There is blood or pus in the stool.

Diarrhoea occurs after foreign travel to anywhere other than Western Europe, North America, Australia or New Zealand.

Diarrhoea is persistent and giardiasis is suspected.

Reassurance is required, as the diagnosis of infection may exclude other pathologies.

The person has recently received antibiotics or been in hospital.

The person is immunocompromised.

Seek advice from the local health protection unit in the following circumstances, as samples may be required:

Suspected public health hazard, for example diarrhoea in food handlers, healthcare workers, elderly residents in care homes, or in people in other high risk situations.

Outbreaks of diarrhoea in the family or community, when isolating the organism may help pinpoint the source of the outbreak.

Contacts of people infected with certain organisms, for example Escherichia coli O157, where there may be serious clinical sequelae to an infection.

How to send a stool sample to the laboratory

Send a single specimen (1 mL, or a pea-sized sample, is the minimum needed for routine investigation) for culture and sensitivity.

If the person has recently travelled abroad to anywhere other than Western Europe, North America, Australia or New Zealand, also request tests for ova, cysts, and parasites.

If diarrhoea is recurrent, and parasitic infection is suspected, send three specimens (5 mL each) 2–3 days apart, as ova, cysts, and parasites are shed intermittently.

Ensure the following details are stated on the request form:

Clinical features (for example systemic illness, fever, bloody stool, abdominal pain; and onset, duration, and recurrence of symptoms).

History of immunosuppression.

Food intake (for example barbecue, restaurant, types of food eaten).

Recent foreign travel — state which country.

Recent antibiotic or proton pump inhibitor, or hospital admission in the last 8 weeks.

Exposure to untreated water, for example drinking water or whilst swimming.

Contact with other affected individuals or outbreaks.

For more information on how to advise the person to take a stool sample, see Collection of stool samples.

In most otherwise healthy adults, encouraging fluid intake (especially if supplemented with fruit juice and soups) will be sufficient.

In adults who are at increased risk of a poor outcome (for example people who are 60 years of age or older, frail, or with comorbidities with which dehydration, hypovolaemia, or haemoconcentration would be a problem, such as cardiovascular disease or thrombotic tendencies), consider supplementing fluid intake with oral rehydration salt solution.

Consumption of solid food should be guided by appetite.

Advise the person to eat small, light meals and avoid fatty, spicy, or heavy food.

Hands should be washed thoroughly with (preferably liquid) soap in warm running water and dried after going to the toilet, changing babies' nappies, and before preparing or serving food or eating meals.

Towels and flannels should not be shared.

A flush toilet should be used if possible. If a commode or bedpan must be used, it should be handled with gloves, the contents disposed of into the toilet, and the container then washed with hot water and detergent and allowed to dry.

Soiled clothing and bed linen should be washed separately from other clothes at the highest temperature they will tolerate (for example 60°C or higher for linen) after removal of excess faecal matter into the toilet. Soaking in disinfectant is not necessary. Do not fill the machine more than half-full to allow for adequate washing and rinsing.

Toilet seats, flush handles, wash-hand basin taps, surfaces, and toilet door handles should be cleaned at least daily with hot water and detergent. Also use disinfectant to clean toilets if available. Use a disposable cloth or one dedicated for toilet use.

Advise exclusion from work or other institutional settings until at least 48 hours after the person is free from diarrhoea and vomiting. Public health authorities will advise if a pathogen is isolated from the person's stool sample (for example Salmonella, Escherichia coli O157): longer periods of exclusion are required in some circumstances.

If cryptosporidiosis is suspected or confirmed, avoid entering swimming pools for 2 weeks after the last episode of diarrhoea.

Antidiarrhoeal drugs are not usually necessary for the management of gastroenteritis.

Antimotility drugs may be useful for symptomatic control in adults with mild-to-moderate diarrhoea, for example if quicker resolution of diarrhoea would enable the person to continue essential activities.

If required, loperamide is the antimotility drug of choice.

Avoid antimotility drugs if there is blood and/or mucus in the stools, or high fever (indicating dysentery).

Antibiotics are not recommended for adults with acute diarrhoea of unknown pathology.

Antibiotics may be appropriate when gastroenteritis is due to a known microbiological cause (see Confirmed microbiological pathogen).

Anti-emetics are not usually necessary for the primary care management of gastroenteritis.

Anti-emetics (such as metoclopramide 10 mg intramuscularly) can be helpful in adults if the person is vomiting severely.

Advise the person to seek medical advice if:

Their condition does not improve within 48 hours.

Symptoms exacerbate or their condition worsens.

Warning signs or symptoms develop (such as severe vomiting or dehydration, persistent fever, abdominal distension, or frank blood in stools).

Notify the Local Authority Proper Officer (in England and Wales, the local Consultant in Communicable Disease Control) if a case of any of the following is suspected:

Cholera.

Bloody diarrhoea presumed to be due to gastroenteritis.

Food poisoning (organisms that can be implicated in food poisoning include Campylobacter, Escherichia coli O157:H7, Salmonella, Shigella, Giardia, Yersinia enterolytica, Entamoeba histolytica, and norovirus).

Haemolytic uraemic syndrome (HUS).

Complete an official Formal Notification Certificate (from a pad supplied locally) immediately on diagnosis of a suspected notifiable disease and return it to where the pad was obtained within 3 days (this could be the Local Authority, Primary Care Trust, or Health Protection Unit).

If urgent notification is needed (such as for suspected cholera, infectious bloody diarrhoea, haemolytic uraemic syndrome, clusters or outbreaks of food poisoning) telephone the local Health Protection Unit with the details. A Formal Notification Certificate must still be sent within 3 days.

Notify and act on the advice of the public health authorities if an outbreak of gastroenteritis is suspected.

Contact details for Health Protection Units in England can be found through the Local and Regional Services page on the Health Protection Agency website www.hpa.org.uk and for health protection teams for Wales on the National Public Health Service for Wales website www.wales.nhs.uk.