Recommendations
Urgent
Prevent or treat dehydration, as required with oral or intravenous fluids.
Be particularly vigilant in the very old.
Dehydration can lead to hypovolaemic shock, coma, and death.[3]
Assess whether the patient needs urgent fluid resuscitation. Indicators include:[14]
Systolic blood pressure less than 100 mmHg
Heart rate more than 90 beats per minute
Cold peripheries
Respiratory rate more than 20 breaths per minute
National Early Warning Score (NEWS2) National Early Warning Score (NEWS) 2 Opens in new window of 5 or more.
Fluid resuscitation will be required in the patient with shock. Use an Airway, Breathing, Circulation, Disability, Exposure (ABCDE) approach to manage shock empirically. Ensure a patent airway and give oxygen if needed.
In the community, refer the patient to hospital if:[11]
They are vomiting and cannot retain fluids
They have comorbidities that increase the risk of complications
They have fever, bloody diarrhoea, or abdominal pain and tenderness
You suspect shock or severe dehydration
The diarrhoea has lasted for more than 10 days (and is severe).
Monitor for progression or rapid deterioration of symptoms.
Key Recommendations
Initial management
Assess hydration status. Initial treatment is to prevent or treat dehydration.[23]
Patients with mild and uncomplicated cases of viral gastroenteritis, where the patient has no sign of dehydration, can be safely treated at home.[17][22]
Advise the patient to maintain an adequate fluid intake to prevent dehydration.[22]
In the community, explain that the patient should return for a follow-up appointment or present to the emergency department if:[22]
Their symptoms do not improve within 48 hours
Their symptoms worsen
Severe vomiting or dehydration, persistent fever, abdominal distension, or frank blood in stools develop.
Supplemental treatment
Normal feeding should continue for patients with no dehydration and can resume immediately after correction of dehydration if present.[17]
The patient should eat as and when they feel able to. Avoid restricted diets.
Advise the patient on how to reduce the risk of transmission, for example:[12]
Wash hands often with soap and water, particularly after using the toilet
Do not prepare food or drinks for other people
Do not share towels or flannels
Flush away any infected faeces or vomit in the toilet and disinfect the surrounding area. Flush the toilet with the lid down.
Rehydration therapy
Replace lost fluid and electrolytes using an oral rehydration solution.
In patients in need of rehydration:
Use a reduced osmolarity oral rehydration regimen (50-60 mmol/L [50-60 mEq/L] sodium) in patients who can tolerate oral fluids as the first-line treatment for mild to moderate dehydration in adults with acute or severe diarrhoea from any cause[3][17][19][26]
Rehydrate the patient over 3 to 4 hours (except in hypernatraemic dehydration, in which case rehydration should occur more slowly over 12 hours)[26]
Avoid fluids high in sugar and very low in sodium (such as some fruit juices) as these may exacerbate diarrhoea.[17]
Use intravenous fluids for patients with signs of shock or severe dehydration, or in patients unable to tolerate oral fluids.
Use an intravenous fluid management plan and regularly monitor patients.[14]
Pharmacotherapy
Do not routinely use anti-emetic or antidiarrhoeal drugs.[23]
The main goals of treatment of viral gastroenteritis are to:
Prevent and treat volume depletion
Maintain nutrition
Reduce transmission of the virus to other people.
Most patients manage themselves at home. Older, frail or immunocompromised patients may need more active treatment and monitoring. This may include starting intravenous fluids in patients who develop viral gastroenteritis as hospital inpatients.
Assess hydration status to determine the immediate management. Initial treatment is to prevent or treat dehydration.[23]
In patients with no indication of requiring intravenous fluid resuscitation, initiate oral rehydration. See our section on intravenous fluids below for indicators of severe dehydration that may require urgent fluid resuscitation.
Mild and uncomplicated viral gastroenteritis, where the patient has no sign of dehydration, can be safely treated by the patient at home.[17][22] Advise the patient to maintain an adequate fluid intake to prevent dehydration.[22]
In the community, explain that the patient should return for a follow-up appointment or present to the emergency department if:[22]
Their symptoms do not improve within 48 hours
Their symptoms worsen
Severe vomiting or dehydration, persistent fever, abdominal distension, or frank blood in stools develop.
Oral rehydration
Replace fluid and electrolytes lost through diarrhoea by giving solutions containing sodium, potassium, and glucose (or another carbohydrate).[26] Older patients or those with comorbidities may be at increased risk from the effects of dehydration.[23] They may require intravenous fluids.
In patients in need of rehydration:
Use a reduced osmolarity oral rehydration solution (50-60 mmol/L [50-60 mEq/L] sodium) as the first-line treatment for mild to moderate dehydration in adults with acute or severe diarrhoea from any cause[3][17][19][26]
Rehydrate the patient over 3 to 4 hours (except in hypernatraemic dehydration in which case rehydration should occur more slowly over 12 hours)[26]
Reassess the patient after initial rehydration. Continue with rapid fluid replacement if the patient is still dehydrated[26]
Avoid fluids high in sugar and very low in sodium (such as some fruit juices) as these may exacerbate diarrhoea[17]
Once rehydrated, prevent further dehydration by encouraging the patient to drink normal volumes of an appropriate fluid and by replacing continuing losses with an oral rehydration solution.[26]
Oral rehydration solution should enhance the absorption of water and electrolytes, and replace the electrolyte deficit adequately and safely.[26]
It contains an alkalinising agent to counter acidosis and is slightly hypo-osmolar (about 250 mmol/L) to prevent the possible induction of osmotic diarrhoea.[26]
The World Health Organization (WHO) oral rehydration salts formulation contains:[26]
Sodium chloride 2.6 g
Potassium chloride 1.5 g
Sodium citrate 2.9 g
Anhydrous glucose 13.5 g.
It is dissolved in sufficient water to produce 1 L (providing sodium 75 mmol/L, potassium 20 mmol/L, chloride 65 mmol/L, citrate 10 mmol/L, glucose 75 mmol/L).
This formulation is recommended by the WHO and the United Nations Children's fund, but it is not commonly used in the UK. In the UK, formulations are lower in sodium (50-60 mmol/L [50-60 mEq/L]) than the WHO formulation, because the sodium loss is usually less severe.[26]
Practical tip
Fluid challenge with a syringe or straw. Give the fluid slowly: for example, 10 mL over 10 minutes. See whether the patient can tolerate it for an hour. This will test whether the patient can tolerate oral fluids and reassure the patient if they can retain the fluid.
Intravenous fluids
Use intravenous fluids for patients with signs of shock or severe dehydration, or in patients unable to tolerate oral fluids.
Indicators that the patient may need urgent fluid resuscitation include:[14]
Systolic blood pressure less than 100 mmHg
Heart rate more than 90 beats per minute
Cold peripheries
Respiratory rate more than 20 breaths per minute
National Early Warning Score (NEWS2) National Early Warning Score (NEWS) 2 Opens in new window of 5 or more.
Patients who develop viral gastroenteritis while in hospital, particularly those who are old and frail, may be started on intravenous fluids, with regular monitoring, at an earlier stage.
Evidence from critically ill patients in general (not specifically patients with viral gastroenteritis) suggests that there is no difference in benefit between normal saline and a balanced crystalloid (such as Hartmann's solution, [also known as Ringer's lactate], or PlasmaLyte®), and therefore either choice of fluid is reasonable.[27] [28] Check local protocols for specific recommendations on fluid choice.
Practical tip
Be aware that large volumes of normal saline as the sole fluid for resuscitation may lead to hyperchloremic acidosis.
Also note that use of lactate-containing fluid in a patient with impaired liver metabolism may lead to a spuriously elevated lactate level, so results need to be interpreted with other markers of volume status.
Use an intravenous fluid management plan with details of the fluid and electrolyte prescription over the next 24 hours, plus plans for assessment and monitoring. This should be reviewed by an expert daily.[14]
Regularly monitor patients receiving intravenous fluids.[14]
Clinical monitoring should include current status of:
NEWS2 score National Early Warning Score (NEWS) 2 Opens in new window
Fluid balance charts
Weight.
Laboratory investigations should include:
Full blood count
Urea
Creatinine
Electrolytes.
Seek expert help if patients have a complex fluid and/or electrolyte redistribution issue or imbalance, or a significant comorbidity, such as:[14]
Gross oedema
Sepsis
Hyponatraemia or hypernatraemia
Renal, liver, and/or cardiac impairment
Post-operative fluid retention and redistribution
Malnourishment and refeeding issues.
Evidence: Choice of fluid
Evidence from two large randomised controlled trials (RCTs) suggests there is no difference between normal saline and a balanced crystalloid in mortality at 90 days, and therefore either option is a reasonable choice for the resuscitation of critically ill patients.
There has been extensive debate over the choice between normal saline (an unbalanced crystalloid) versus a balanced crystalloid (such as Hartmann’s solution [also known as Ringer’s lactate] or Plasma-Lyte®). Evidence from critically ill patients points to no benefits from using a balanced crystalloid in preference to normal saline. Clinical practice varies widely, so you should check local protocols.
In 2021 to 2022 two large double-blind RCTs were published assessing intravenous fluid resuscitation in intensive care unit (ICU) patients with a balanced crystalloid solution (Plasma-Lyte) versus normal saline. The Plasma-Lyte 148 versus Saline (PLUS) trial (53 ICUs in Australia and New Zealand; N=5037) and the Balanced Solutions in Intensive Care Study (BaSICS) trial (75 ICUs in Brazil; N=11,052), was published in 2021.[28][27]
In the PLUS study 45.2% of patients were admitted to ICU directly from surgery (emergency or elective), 42.3% had sepsis and 79.0% were receiving mechanical ventilation at the time of randomisation.
In BaSICS almost half the patients (48.4%) were admitted to ICU after elective surgery and around 68% had some form of fluid resuscitation before being randomised.
Both found no difference in 90-day mortality overall or in pre-specified subgroups for patients with acute kidney injury (AKI), sepsis, or post-surgery. They also found no difference in the risk of AKI.
In BaSICS, for patients with traumatic brain injury, there was a small decrease in 90-day mortality with normal saline - however, the overall number of patients was small (<5% of total included in the study) so there is some uncertainty about this result. Patients with traumatic brain injury were excluded from PLUS as the authors felt these patients should be receiving saline or a solution of similar tonicity.
One meta-analysis of 13 RCTs (including PLUS and BaSICS) confirmed no overall difference, although the authors did highlight a non-significant trend towards a benefit of balanced solutions for risk of death.[29]
Previous evidence has been mixed.
One 2015 double-blind, cluster-randomised, double-crossover trial conducted in four ICUs in New Zealand (N=2278), the 0.9% Saline vs. Plasma-Lyte for ICU fluid Therapy (SPLIT) trial, found no difference for in-hospital mortality, AKI, or use of renal-replacement therapy. [30]
However, one 2018 US multicentre unblinded cluster-randomised trial - the isotonic Solutions and Major Adverse Renal events Trial (SMART), among 15,802 critically ill adults receiving ICU care - found possible small benefits from balanced crystalloid (Ringer’s lactate or Plasma-Lyte) compared with normal saline. The 30-day outcomes showed a non-significant reduced mortality in the balanced crystalloid group versus the normal saline group (10.3% vs. 11.1%; OR 0.90, 95% CI 0.80 to 1.01) and a major adverse kidney event rate of 14.3% versus 15.4% respectively (OR 0.91, 95% CI 0.84 to 0.99).[31]
One 2019 Cochrane review included 21 RCTs (N=20,213) assessing balanced crystalloids versus normal saline for resuscitation or maintenance in a critical care setting.[32]
The three largest RCTs in the Cochrane review (including SMART and SPLIT) all examined fluid resuscitation in adults and made up 94.2% of participants (N=19,054).
There was no difference in in‐hospital mortality (OR 0.91, 95% CI 0.83 to 1.01; high quality evidence as assessed by GRADE), acute renal injury (OR 0.92, 95% CI 0.84 to 1.00; GRADE low), or organ system dysfunction (OR 0.80, 95% CI 0.40 to 1.61; GRADE very low).
Shock
Use an Airway, Breathing, Circulation, Disability, Exposure (ABCDE) approach to manage shock empirically. Ensure a patent airway and give oxygen if needed. Treat the underlying cause as early as possible. Escalate all patients with shock to a senior clinician. Fluid resuscitation will be required.
See Shock for full management recommendations.
There is no specific treatment for viral gastroenteritis.
Anti-emetics
Do not routinely use anti-emetics. They are not usually necessary and may have an adverse effect of masking symptoms.[23]
In patients with mild or moderate volume depletion, consider an anti-emetic, such as cyclizine or ondansetron, only for those with intractable vomiting and who are unable to tolerate oral fluids. Consider using in patients on intravenous fluids when required for symptomatic relief.
Metoclopramide is another option, but has an increased risk of adverse effects.
The risk of neurological effects with metoclopramide, such as tardive dyskinesia and extrapyramidal disorders, outweighs the benefits with long-term use or with high doses. Only prescribe the recommended dose for short-term use (up to 5 days).[33]
Antidiarrhoeals
Do not routinely use antidiarrhoeals. They are not usually necessary and may have an adverse effect of masking symptoms.[23]
Avoid antidiarrhoeals in patients with bloody diarrhoea (which may indicate a bacterial cause) or where an inflammatory cause is suspected, as it may prolong the infection.[13]
Intestinal motility promotes clearance of infecting bacterial pathogens, such as Salmonella, Shigella, Escherichia coli, and Clostridium difficile. If this clearance is prohibited, the bacteria may proliferate and penetrate the epithelium, leading to a worse clinical outcome.[34]
In particular, the pathogenesis of C difficile disease is mediated by toxins. Decreased intestinal peristalsis caused by antimotility agents may allow for increased contact time between organisms such as C difficile, the toxins produced, and the mucosal epithelium.[34]
In practice, antidiarrhoeals, such as loperamide, may be used as a specific strategy for short-term symptom management: for example, if a patient has to travel.
The patient should eat as and when they feel able to. Restricted diets are unnecessary.[17]
Normal feeding should continue for patients with no dehydration and can resume immediately after correction of dehydration if present.[17]
The patient can be discharged once they can tolerate oral fluids, providing that they are well and that electrolyte disturbances have been resolved.
Do not discharge patients to nursing or residential homes (if they are free of a viral gastroenteritis outbreak) or to other hospitals until the patient has been asymptomatic for at least 48 hours (urgent transfers will require individual risk assessment).[23]
Advise the patient that if symptoms develop after discharge they or their carers should inform their general practitioner.[10]
Ask about the patient’s occupation, as there can be implications for certain professions, such as food handlers and healthcare professionals.[11][19]
Advise the patient on how to reduce the risk of transmission:[12]
Wash your hands often with soap and water, particularly after using the toilet
Do not prepare food or drinks for other people
Do not share towels or flannels
Disinfect any hard surfaces or objects that an infected person has touched
Wash any clothing or bedding that could have become contaminated with the virus. Wash the items separately and on a hot wash
Flush away any infected faeces or vomit in the toilet and disinfect the surrounding area. Flush the toilet with the lid down.
During a period of increased incidence of diarrhoea and/or vomiting, isolate patients in single rooms (as should happen for single cases) or cohort nurse in bays if resource allows.[23] Follow outbreak control measures.[23]
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