Vomiting in Children Algorithm

Safety

Red Flags — Exclude surgical and life-threatening causes first

Done

Scope: this pathway supports initial primary-care assessment of vomiting in children aged 0–12 years. NICE CG84 recommendations on gastroenteritis and dehydration apply specifically to children under 5 years. Children aged 5 years and over require age-appropriate clinical judgement and local paediatric acute assessment pathways; also use NICE NG143 where fever is present in under 5s, NICE NG18 where diabetes/DKA is suspected, and relevant abdominal, neurological and safeguarding pathways. Confirmed green/bile-stained vomiting requires immediate paediatric/surgical assessment.

Bilious (green) vomiting Any age — possible malrotation with volvulus, intussusception, bowel obstruction → immediate paediatric/surgical assessment; 999 if unstable, shocked, collapsed or reduced consciousness. A well-appearing child with a single uncertain episode of yellow or yellow-green vomit still needs immediate (same-day) clinical assessment.

Projectile vomiting — infant Progressive or projectile vomiting, especially under 2 months; hungry after vomiting; olive mass not always palpable → possible pyloric stenosis → Same-day specialist assessment

Altered consciousness + vomiting Raised ICP, meningitis, encephalitis, intracranial bleed → 999

Haematemesis Fresh blood or coffee-ground vomit — swallowed blood, mucosal trauma after retching (Mallory-Weiss), oesophagitis, ulceration, rarely varices → same-day hospital assessment (A&E); 999 for ongoing or large-volume bleeding, haemodynamic compromise, pallor, collapse, altered consciousness or suspected significant upper GI bleeding

Suspected shock Altered consciousness, weak pulses, mottled/pale skin, cold extremities, hypotension, markedly prolonged CRT or severe respiratory abnormality → 999 — emergency transfer and resuscitation support. Interpret CRT with mental state, pulse quality, heart rate, skin colour, urine output, breathing and BP — not as a standalone threshold.

Vomiting + severe abdominal pain Appendicitis, peritonitis, pancreatitis, volvulus, intussusception → 999 or same-day surgical. Bilious vomiting, abdominal distension, severe/localised pain and rebound tenderness suggest a diagnosis other than gastroenteritis (NICE CG84).

Diabetic ketoacidosis (DKA) Polyuria, polydipsia, weight loss, abdominal pain, vomiting, dehydration, hyperventilation or reduced consciousness; or vomiting/abdominal pain in a child with known diabetes (DKA possible even with normal glucose) → Immediate hospital assessment — contact paediatric diabetes team/emergency service

Vomiting + headache + photophobia Meningitis, subarachnoid haemorrhage → 999

Suspected poisoning / ingestion Vomiting after possible toxic ingestion → assess ABCDE; clinicians use TOXBASE or contact NPIS (professional service — not for families). Advise the public to use NHS 111; 999 for collapse, seizures, respiratory compromise, reduced consciousness or a potentially life-threatening ingestion. Not every ingestion needs 999.

Vomiting + urticarial rash Anaphylaxis → 999 + IM adrenaline immediately

Bilious vomiting (green bile) in a neonate or infant is a surgical emergency — malrotation with midgut volvulus can cause complete intestinal ischaemia within hours if untreated. It is incompatible with survival without emergency surgery. Never attribute bilious vomiting to feeding problems in neonates.

Pyloric stenosis peaks at 4–6 weeks (range 2–8 weeks), is more common in boys, and presents with projectile non-bilious vomiting after feeds, a visibly hungry child (not ill), and hypochloraemic hypokalaemic metabolic alkalosis on bloods. The "olive" is not always palpable. US is confirmatory.

DKA in previously undiagnosed T1DM can present as a flu-like illness with vomiting. In a vomiting child with polyuria, polydipsia, weight loss, fatigue or hyperventilation, check capillary glucose (and blood ketones where available). Do not diagnose DKA in primary care from glucose and urine ketones alone — NICE NG18 defines DKA by acidosis (pH <7.3 or bicarbonate <15 mmol/L) with ketonaemia >3 mmol/L or urine ketones ≥++, usually with glucose >11 mmol/L.

Diagnose

Characterise the vomiting — pattern, content, timing

Done

Acute (<1 week)

Gastroenteritis (most common), viral illness, UTI, AOM, appendicitis, intussusception, DKA, poisoning, post-tussive.

Recurrent / episodic

Cyclical vomiting syndrome (CVS), abdominal migraine, GORD, coeliac, food allergy, anxiety, constipation-related, metabolic disorder.

Bilious vs non-bilious

Confirmed green/bile-stained = possible obstruction/volvulus — immediate paediatric/surgical assessment. Non-bilious = above ligament of Treitz — gastritis, GORD, pyloric stenosis, systemic cause.

Projectile vs effortless

Projectile = pyloric stenosis (infant), raised ICP, severe gastritis. Effortless/regurgitation = GORD in infants. Post-tussive = cough-induced in pertussis.

Onset / relation to feeds

During feeds / shortly after = GORD, overfeeding. 30–60 min after = pyloric stenosis. 2–6hrs after meal = food poisoning / gastroenteritis. Unrelated to feeding = systemic cause.

Associated symptoms

Diarrhoea → gastroenteritis. Fever → infective. Headache / photophobia → CNS. Polyuria → DKA. Colicky pain + "redcurrant jelly" PR → intussusception. RIF pain → appendicitis.

Age pattern

<3mo: GORD, pyloric stenosis, metabolic, NAI. 3–12mo: gastroenteritis, intussusception, URTI. 1–5yr: gastroenteritis, UTI, constipation. 5–12yr: appendicitis, CVS, migraine, anxiety, GORD.

Is it gastroenteritis?

Gastroenteritis = sudden vomiting and/or sudden change to loose or watery stools. Do not diagnose gastroenteritis from vomiting alone without considering alternatives. Ask about: fever; diarrhoea and blood/mucus; urine output and fluid intake; bilious or bloody vomit; abdominal pain/distension; headache or neurological symptoms; polyuria/polydipsia/weight loss; recent travel, outbreak or toxin exposure; feeding and weight trajectory; medication and safeguarding history.

The timing and content of vomiting is the most important differentiating feature. "Redcurrant jelly" stool (bloodstained mucus) with colicky pain and vomiting in a 6–18 month old is intussusception until proven otherwise — this is a classic MRCGP and SCA scenario. Call 999 and document clearly.

Cyclical vomiting syndrome (CVS) is under-diagnosed — stereotyped episodes lasting 1–5 days with complete symptom-free periods between them, often triggered by stress or illness, frequently with a family history of migraine. Acute and preventive treatment, including any antiemetic, is specialist-led through the local paediatric pathway.

Diagnose

Assess dehydration severity — NICE CG84 framework

Done

Dehydration is the primary complication of vomiting and drives the admission decision. NICE CG84 classifies hydration as no clinically detectable dehydration, clinical dehydration or shock — individual signs are imperfect, so interpret them together and do not assign a numerical percentage. If uncertain, manage towards the more severe category.

No clinically detectable dehydration

Alert and responsive. Normal colour. Normal urine output. Moist mucous membranes. Normal skin turgor. Normal peripheral pulses. Normal breathing pattern. Appears well. → Manage at home: continue breast/formula feeds and usual fluids; ORS supplementation if at increased risk of dehydration.

Clinical dehydration

Altered or reduced responsiveness. Appears unwell or deteriorating. Reduced urine output. Dry mucous membranes. Tachycardia. Tachypnoea. Abnormal skin turgor. Sunken eyes. Prolonged CRT. → Low-osmolarity ORS 50 mL/kg over 4 hours plus maintenance, with regular reassessment; consider NG ORS (hospital) if unable to drink or persistently vomiting ORS.

Shock

Reduced level of consciousness. Pale or mottled skin. Cold extremities. Weak peripheral pulses. Hypotension (late sign). Markedly prolonged CRT. Severe tachycardia or bradycardia. Respiratory compromise. → 999 immediately — emergency transfer; fluids per local paediatric resuscitation pathway.

Urine output guide

Ask about urine output and wet nappies. Reduced urine output, particularly with poor intake, dry mucosa, lethargy, tachycardia or abnormal perfusion, requires urgent assessment. Complete anuria, severe dehydration or associated lethargy/shock requires emergency care.

Signs to monitor

Weight (if available — most accurate measure). Heart rate for age. Blood pressure (late sign — normal BP can mask significant dehydration in children). Mucous membranes and anterior fontanelle (infants).

The NICE CG84 framework (no clinically detectable dehydration / clinical dehydration / shock) guides fluid management decisions in under 5s. Skin turgor ("tenting") is less reliable in obese children. The most reliable bedside signs are: dry mucous membranes, sunken eyes, tachycardia, and reduced skin perfusion. No single sign is reliable — interpret signs together.

Blood pressure is a late sign of dehydration in children — children compensate well and can maintain a normal BP until late. Tachycardia is an earlier and more sensitive marker. A normal BP does NOT rule out significant dehydration.

Diagnose

Targeted Examination — identify the cause

Done

General impression

ABCDE first. Is child alert, interactive, consolable? Lethargic / unrousable → HIGH RISK. Dehydration signs (as Step 3). Assess hydration first in every vomiting child.

Abdomen

Look for distension, focal tenderness (RIF = appendicitis; epigastric = gastritis/peptic ulcer), guarding or rigidity, palpable mass (intussusception — "sausage" shape RUQ) and herniae; examine testes where indicated. Gastroenteritis may cause diffuse discomfort, but focal or severe pain should prompt consideration of surgical or other diagnoses. Peritonism (guarding, rebound) → surgical emergency. Bowel sounds are not reliable for diagnosing ileus or peritonitis.

Neurological

Level of consciousness/GCS, abnormal behaviour, pupils, focal neurological signs, seizure, ataxia, visual symptoms, fontanelle (bulging in infants). Raised ICP = vomiting + progressive or morning headache, reduced consciousness, abnormal pupils, focal signs / sunset sign in infants. Fundoscopy for papilloedema is not a practical primary-care test and its absence does not exclude raised ICP. Non-blanching rash = meningococcal.

ENT

Ears (AOM → vomiting especially in young child). Throat (tonsillitis, pharyngitis). Cervical lymphadenopathy. Post-nasal drip can cause nausea/vomiting.

Urine testing

Consider urine testing where there is fever without an alternative focus, poor feeding, lethargy, irritability, urinary symptoms, abdominal pain, offensive urine, haematuria or unexplained illness. Do not routinely test a well child with a clear alternative diagnosis. Do not overinterpret ketonuria as DKA, trace blood as UTI, isolated glycosuria, or dipstick results without a properly collected sample.

Blood glucose

Check capillary glucose if diabetic symptoms, significant systemic illness, altered consciousness, dehydration or diagnostic uncertainty (local practice — not a NICE CG84 requirement). Glucose >11 mmol/L with compatible symptoms → suspect DKA and arrange immediate hospital assessment; check blood ketones where available. DKA cannot be diagnosed from glucose and ketones alone. Hypoglycaemia: manage per local hypoglycaemia protocol (depends on symptoms, age, diabetes status and ability to take oral glucose safely).

UTI can present with vomiting in infants without localising urinary symptoms, so test urine when UTI is clinically plausible (NICE NG224); infants under 3 months with suspected UTI need immediate paediatric referral. Most children with gastroenteritis do not need laboratory investigations (NICE CG84). Missing UTI leads to pyelonephritis, bacteraemia, and renal scarring.

DKA is increasingly diagnosed in primary care as T1DM incidence rises. In new-onset T1DM, the presentation mimics gastroenteritis — vomiting, abdominal pain, and malaise. Checking capillary glucose (and blood ketones where available) in any child with unexplained vomiting + any of polyuria, weight loss, polydipsia or excessive tiredness helps identify possible DKA early — refer immediately if suspected; do not try to confirm DKA in primary care.

Diagnose

Investigations

Done

Urine testing

Selective Only if UTI is clinically plausible (NICE NG224): fever without an alternative focus, poor feeding, lethargy, irritability, urinary symptoms, abdominal pain, offensive urine, haematuria or unexplained illness. Not routine in a well child with a clear alternative diagnosis. Infants under 3 months with suspected UTI → immediate paediatric referral.

Blood glucose (BM)

Selective If diabetic symptoms, significant systemic illness, altered consciousness, dehydration or diagnostic uncertainty. Blood ketones if DKA is possible. Glucose >11 mmol/L with compatible symptoms → suspect DKA, immediate hospital assessment. Low glucose → follow local hypoglycaemia protocol.

Stool culture

Perform if: suspected septicaemia; blood or mucus in stool (Campylobacter, STEC/E. coli O157); immunocompromised. Consider if: recent overseas travel; diarrhoea not improved by day 7; diagnostic uncertainty; suspected outbreak. Not routine for uncomplicated gastroenteritis. If STEC suspected or confirmed: no antimotility agents; seek specialist/public-health advice on monitoring for HUS.

FBC + U&E + venous gas

Not indicated in uncomplicated gastroenteritis. Appropriate when significant dehydration or shock is present, IV fluids are needed, hypernatraemia or acidosis is suspected, DKA is suspected, or sepsis/another systemic illness is suspected — usually arranged by the receiving paediatric team.

AXR

NOT routine for vomiting. Suspected obstruction → urgent paediatric/surgical assessment; imaging is determined by the receiving team and local radiology pathway. Do not delay transfer to obtain an AXR.

Abdominal ultrasound

Hospital investigation via the paediatric/surgical team. Progressive or projectile vomiting in an infant, especially under 2 months, requires same-day specialist assessment for possible pyloric stenosis. Intussusception ("target sign"). Appendicitis (graded compression USS).

Most children with gastroenteritis need no laboratory investigations (NICE CG84). Investigate selectively: urine when UTI is clinically plausible, capillary glucose and blood ketones when DKA is possible — targeted testing detects serious diagnoses (UTI, DKA) that are commonly missed.

Stool culture for routine gastroenteritis has a very low yield and rarely changes management. NICE CG84: perform stool microbiology if septicaemia is suspected, there is blood or mucus in the stool, or the child is immunocompromised; consider it after recent overseas travel, if diarrhoea has not improved by day 7, with diagnostic uncertainty or a suspected outbreak.

Refer

Referral Criteria

Done

999

Airway, breathing or circulatory compromise. Reduced consciousness or seizure. Suspected meningitis/encephalitis. Shock. Confirmed bilious vomiting with instability or severe abdominal signs. Suspected volvulus, obstruction, intussusception or peritonitis. Significant haematemesis. Suspected DKA. Severe anaphylaxis. Serious poisoning or toxic ingestion.

Same-day ED

Confirmed bilious vomiting in a well-appearing child (immediate paediatric/surgical assessment). Clinical dehydration not tolerating ORS. Age <3 months with persistent vomiting, fever, poor feeding, dehydration, weight loss, projectile vomiting or abnormal examination (a well infant with uncomplicated posseting is different). Suspected appendicitis / surgical abdomen. Raised capillary glucose with compatible symptoms. Suspected pyloric stenosis (progressive/projectile, especially under 2 months). Unable to assess adequately in primary care.

Same-day paeds

Infant vomiting + faltering growth not explained. Vomiting + suspected metabolic disorder. Failed ORS trial in surgery / repeated same-day visit.

Paeds outpatient

Recurrent vomiting when episodes are unexplained, stereotyped, associated with faltering growth, neurological symptoms, severe pain, dehydration, abnormal examination or persistent symptoms despite appropriate initial management. Suspected CVS (cyclical episodes, family migraine history). Reflux symptoms that do not resolve, or recur after stopping, a 4-week PPI/H2RA trial started for NICE NG1 indications. Suspected food allergy.

Primary care manage

Viral gastroenteritis — well, no clinically detectable dehydration, or clinical dehydration tolerating ORS with reassessment. GORD in thriving infant. Overfeeding. Motion sickness. Post-tussive vomiting with resolving cough.

Intussusception has a classic presentation but also presents atypically — the "redcurrant jelly" stool is a late sign and often absent. The classic presentation is: age 6–18 months, sudden-onset severe colicky pain, pallor, drawn-up legs, vomiting (initially non-bilious, may become bilious), followed by periods of apparent wellness between episodes. Any vomiting infant with unexplained pallor and inconsolable crying should be referred immediately.

Treat

Treatment — ORS, antiemetics, condition-specific management

Done

Gastroenteritis — clinical dehydration

ORS (Dioralyte) First-line

Low-osmolarity ORS 50 mL/kg over 4 hours in addition to maintenance fluids, in small frequent amounts (e.g. 5–10 mL every 1–2 minutes by syringe), with regular reassessment. Consider NG ORS if unable to drink or persistently vomiting ORS. IV fluids (hospital) for shock, deterioration despite ORS, or persistent vomiting despite oral/NG rehydration — follow local paediatric resuscitation guidance. Then resume normal feeds.

GORD — infant

Reassurance + feed review Thriving infant

Thriving infant with effortless regurgitation and no concerning symptoms: reassure — no routine investigation or medication. Do not use positional management in sleeping infants; infants sleep flat on their backs (no prone/side sleeping, cot elevation, inclined products or unsupervised sleep in car seats/bouncers). Frequent regurgitation with marked distress — breastfed: breastfeeding assessment, then if persistent consider alginate for 1–2 weeks. Formula-fed: review feeding history, reduce excessive volumes, trial smaller more frequent feeds (same total daily intake), then thickened formula; if unsuccessful, stop thickened formula and trial alginate for 1–2 weeks (NICE NG1). Alginate (Gaviscon Infant) and anti-reflux formula are different steps and should not generally be combined. Do not use acid suppression for isolated posseting/regurgitation.

Antiemetics

Ondansetron Specialist pathway only

Do not routinely prescribe ondansetron for uncomplicated gastroenteritis in primary care; use only under the local paediatric/secondary-care pathway (restricted/specialist on local formularies). Consider QT prolongation, electrolyte abnormalities, constipation and diarrhoea; avoid in congenital long-QT syndrome. Metoclopramide: contraindicated under 1 year, significant extrapyramidal risk, not routine for gastroenteritis or reflux. Domperidone: not a routine antiemetic in children (cardiac risks); for reflux only with specialist paediatric agreement after other measures (NICE NG1).

GORD — acid suppression

Do not use acid suppression for isolated posseting/regurgitation. Consider a 4-week PPI or H2RA trial only for overt regurgitation with unexplained feeding difficulty, distressed behaviour or faltering growth, in accordance with NICE NG1 and local paediatric prescribing guidance. Review at 4 weeks and refer if symptoms do not resolve or recur after stopping. Check doses in the SPC and your local paediatric formulary.

Motion sickness

Outside the scope of this pathway. Promethazine is not a general treatment for vomiting (sedation, paradoxical excitation, respiratory depression; product- and age-specific), and travel-sickness products are not routinely prescribed (local formulary).

Fluid rehydration guidance

Continue breastfeeding; do not routinely stop formula feeds. Low-osmolarity ORS for clinical dehydration, in small frequent volumes. Usual fluids (including water) are acceptable for a child without dehydration or red-flag features who refuses ORS, but are not equivalent to ORS for clinical dehydration. Avoid fruit juice, carbonated and sugary drinks — osmotic diarrhoea risk. AVOID anti-diarrhoeal agents (loperamide) in children.

Return to diet

Reintroduce normal age-appropriate foods after rehydration — do not recommend a BRAT diet; BRAT diet (banana, rice, apple, toast) is NOT evidence-based. Normal diet resumes faster and reduces illness duration. Offer small, frequent amounts.

Next steps: see Gastroenteritis · Reflux in infants · Surgical problems in children · DKA

ORS via syringe at 5ml every 1–2 minutes works even when children are actively vomiting because small volumes leave the stomach before the vomiting reflex is triggered. A Cochrane review (2006) found ORS as effective as IV rehydration for mild-moderate dehydration and associated with shorter hospital stays. Demonstrating the technique to parents in the surgery dramatically improves compliance.

Metoclopramide (neurological/extrapyramidal adverse effects, MHRA) and domperidone (cardiac risks) are not routine antiemetics in children and not routine treatments for gastroenteritis or reflux; for reflux, NICE NG1 requires specialist paediatric agreement after other measures have been tried. MHRA (December 2019): domperidone is no longer licensed for children under 12 years or weighing under 35 kg; MHRA (2013): metoclopramide is contraindicated under 1 year and restricted to second-line specific indications in under 18s. NICE CG84 notes ondansetron can reduce vomiting and facilitate ORS but may increase diarrhoea, and does not recommend routine primary-care prescribing; it carries a dose-dependent QT-prolongation risk (MHRA), particularly with electrolyte imbalance from dehydration, so use only within the local paediatric pathway.

Lifestyle

Supportive Care, Hygiene & Prevention

Done

Hand hygiene Wash hands with soap and water after toileting/nappy changes and before food preparation — preferred over alcohol gel, particularly for norovirus. Key message for whole household; follow local infection-control advice during outbreaks.

Exclusion from nursery/school Minimum 48 hours after last episode of vomiting or diarrhoea. Do not return earlier regardless of apparent recovery. Inform school/nursery if confirmed Salmonella / VTEC — longer exclusion required per UKHSA guidance (Health protection in children and young people settings).

Rotavirus vaccination Oral Rotarix given at about 8 and 12 weeks (UK schedule). Preventative — it does not treat current gastroenteritis. Postpone a due dose during acute diarrhoea or vomiting, then give it once recovered within the strict age limits: first dose before 15 weeks, course completed before 24 weeks (Green Book chapter 27b). Check vaccination status.

GORD — feeding advice Overfeeding is common cause of vomiting in formula-fed infants. Check feed volumes (150ml/kg/day for newborns). Holding upright while awake after a feed may be discussed as a comfort measure only — infants must sleep flat on their backs (no prone/side sleeping, cot elevation, inclined sleep products or unsupervised sleep in car seats/bouncers). Formula-fed with marked distress: smaller, more frequent feeds, then thickened (anti-reflux) formula, then alginate only if that fails — thickened formula and alginate (Gaviscon Infant) are separate steps and not interchangeable (NICE NG1).

Surface disinfection During gastroenteritis: clean surfaces promptly after vomit or diarrhoea using a disinfectant at the concentration specified by the product and local infection prevention and control (IPC) guidance. Wash vomit-contaminated laundry at 60°C.

Food safety For food poisoning prevention: refrigerate promptly, reheat thoroughly, wash hands before food preparation, separate raw and cooked meat, avoid raw eggs in young children. FSA "4Cs" message: clean, chill, cook, cross-contamination.

The 48-hour exclusion rule is a public health measure based on viral shedding patterns — norovirus and rotavirus are maximally contagious during and immediately after illness. Returning to school before 48 hours causes secondary cases in classrooms. Food handlers are advised to stay off work until 48 hours symptom-free (FSA guidance), and UKHSA recommends the same for children in communal settings.

Rotavirus vaccination (UK schedule since 2013) is the main intervention for preventing severe rotavirus disease; it is preventative and does not treat current illness. Checking vaccination status during an acute consultation is a brief but valuable quality intervention.

Safety

Follow-up, Safety-Netting & Monitoring

Done

Gastroenteritis — well child

No routine follow-up needed. Vomiting usually lasts 1–2 days and diarrhoea 5–7 days (NICE CG84). Contact the GP the same day or NHS 111 if dehydration worsens, new symptoms appear (blood in stool, fever), vomiting lasts more than 2 days or diarrhoea more than 7 days.

GORD follow-up

Only if a 4-week PPI/H2RA trial was started for NICE NG1 indications: review at 4 weeks; stop where possible, and refer to paediatrics if symptoms do not resolve or recur after stopping. Do not continue long term without specialist input.

First episode vomiting — unexplained

Review within 24 hours if amber features or the cause cannot be confirmed. Under 3 months with persistent vomiting, fever, poor feeding, dehydration, weight loss, projectile vomiting or abnormal examination → same-day ED (Step 6), not a later review. If cause confirmed and child well → safety-net only.

Recurrent vomiting

Review 1–2 weeks to track pattern. Diary of episodes (duration, trigger, associated symptoms) aids diagnosis of CVS / abdominal migraine. Refer paeds if episodes are unexplained, stereotyped, or associated with faltering growth, neurological symptoms, severe pain, dehydration, abnormal examination or persistent symptoms despite initial management.

Call 999 if:

Child becomes floppy / unresponsive, collapses or has a seizure. Difficulty breathing. Suddenly very pale with cold, mottled skin. Vomiting large amounts of blood. Green vomit in a child who is very unwell. Non-blanching rash.

Go to A&E now if:

Green or yellow-green vomit — even if the child seems well. Blood in vomit or vomit that looks like coffee grounds. Signs of DKA (excessive thirst, passing lots of urine, fast or deep breathing). Call 999 if the child is very unwell.

Same day — GP or NHS 111:

Blood in stool. Worsening abdominal pain or distension. Increasing lethargy or reduced responsiveness. Reduced urine output / fewer wet nappies. Persistent vomiting preventing hydration (cannot keep ORS down). Forceful or projectile vomiting in a hungry young baby. A baby under 3 months who keeps vomiting, feeds poorly or has a fever. Vomiting for more than 2 days or diarrhoea for more than 7 days. Parent/carer concern that the child is deteriorating.

Food safety reporting

Suspected food poisoning from restaurant/takeaway → notify local Environmental Health. VTEC / Salmonella typhi / Shigella → notifiable disease (as is suspected food poisoning) — notify the local UKHSA health protection team (Health Protection (Notification) Regulations 2010).

Written safety-net advice reduces ED re-attendance in gastroenteritis (clinical practice). Specific, actionable instructions ("call 999 if vomit turns green") are more effective than generic advice ("come back if worried"). Document that safety-netting was provided.

Gastroenteritis-triggered haemolytic uraemic syndrome (HUS) occurs 5–10 days after E. coli O157 infection — vomiting/diarrhoea resolves, then child develops pallor, reduced urine output, and bruising (microangiopathic haemolytic anaemia + renal failure). Parents should be warned about this specifically if bloody diarrhoea is present. Send stool culture and review in 1 week. If STEC is suspected or confirmed, do not give antimotility agents and seek specialist/public-health advice on monitoring for HUS.