Gastroenterology & Family Medicine & Infectious Diseases
Gastroenteritis | Clinique Omicron Quebec
Acute gastroenteritis (AGE) is an acute inflammation of the gastrointestinal tract—stomach, small intestine, and colon—manifesting as acute diarrhea (≥3 loose or liquid stools per day for less than 14 days), accompanied by nausea, vomiting, and abdominal cramps. It is one of the most frequent conditions in family medicine and pediatrics in Quebec, with over 179 million annual episodes in North America. The vast majority of gastroenteritis cases are viral in origin and self-resolve within 24 to 72 hours—treatment is primarily based on oral rehydration. Bacterial and parasitic causes, which are less frequent, require targeted microbiological investigation and may warrant antibiotic therapy. Dehydration, the main complication in children under 5 years of age, the elderly, and immunocompromised individuals, remains the most significant cause of mortality related to gastroenteritis worldwide—although rare in high-income countries like Quebec due to access to rehydration. The distinction between non-invasive gastroenteritis (enterotoxigenic—secretory diarrhea without fever or blood) and invasive gastroenteritis (dysenteric—bloody diarrhea + fever + fecal leukocytes) is clinically decisive for guiding microbiological workup and therapeutic decisions.
Etiologies, epidemiology, and pathophysiology
- Viral causes — responsible for 70–80% of acute gastroenteritis cases: norovirus (calicivirus): the leading cause of epidemic gastroenteritis in adults and children — responsible for 18% of all global cases of acute gastroenteritis + 50–80% of foodborne outbreaks in developed countries — highly contagious (infectious dose: 18–1,000 virions) — transmission: direct fecal-oral route + aerosols from vomiting (highly effective — a single episode of vomiting disperses millions of viral particles into the air) + contaminated surfaces — resistant to common disinfectants (70% alcohol insufficient → 1,000 ppm chlorine recommended) — incubation: 12–48 hours — duration: 24–72 hours — clinical presentation: predominantly vomiting + diarrhea + cramps + mild fever — typical epidemic settings: long-term care facilities + hospitals + cruise ships + camps + restaurants (mass foodborne illness — foodborne illness outbreak) — mandatory reporting if ≥2 cases linked to the same food source (MAPAQ + DSP Québec); rotavirus: leading cause of severe acute gastroenteritis in children aged 6 months to 2 years worldwide — in Quebec: universal vaccination (oral vaccine Rotarix or RotaTeq — Quebec vaccination program — 2 or 3 doses starting at 2 months) → 85–90% reduction in rotavirus hospitalizations among vaccinated children — clinical presentation: vomiting + watery diarrhea + fever + possible severe dehydration — incubation: 1–3 days — duration: 3–8 days; enteric adenovirus (types 40 and 41): second leading cause of viral gastroenteritis in children — longer incubation period (8–10 days) — longer duration (1–2 weeks) — less vomiting than rotavirus + astrovirus + sapovirus: less common causes — mild clinical presentation — children ++; SARS-CoV-2: gastrointestinal symptoms (diarrhea + nausea + vomiting) in 10–20% of COVID-19 cases — may precede respiratory symptoms — nasopharyngeal PCR if clinical presentation is suggestive
- Bacterial causes – Invasive gastroenteritis and food poisoning: Campylobacter jejuni Most frequent bacterial cause of gastroenteritis in Canada — source: undercooked poultry (chicken++) + untreated water — incubation: 2–5 days — clinical presentation: serosanguineous diarrhea + intense abdominal pain (pseudo-appendicitis) + high fever — rare but severe complications: post-infectious Guillain-Barré syndrome (molecular mimicry LOS-gangliosides) — notifiable disease in Quebec — antibiotic therapy if severe or immunocompromised: azithromycin 500 mg/day × 3 days; ; Salmonella non-typhoidal (S. enteritidis + S. typhimurium): source: raw eggs + poultry + reptiles + amphibians — incubation: 6–72 hours — febrile diarrhea + abdominal pain — bacteremia in 5–10% of cases (elderly + sickle cell patients + immunocompromised) — ODA — antibiotic therapy if severe or bacteremia: ciprofloxacin or azithromycin; ; Shigella Bacillary dysentery - highly contagious (very low infectious dose) - bloody diarrhea + fever + tenesmus + fecal leukocytes - source: fecal-oral (soiled hands) - P.O. medication - antibiotic therapy: azithromycin or ciprofloxacin x 3 days ; Escherichia coli Enterotoxigenic (ETEC): main cause of traveler's diarrhea — LT + ST toxins → watery secretory diarrhea — spontaneous resolution in 3–5 days — rifaximin or azithromycin if severe ; E. coli enterohemorrhagic (EHEC — serotype O157:H7): source: undercooked ground beef + contaminated raw vegetables + water → verotoxin (Shiga toxin-like) → hemorrhagic colitis + hemolytic uremic syndrome (HUS — emergency) → ANTIBIOTICS CONTRAINDICATED in EHEC (risk of increasing shigatoxin release → worsening of HUS) + Staphylococcus aureus (preformed toxin): food poisoning — vomiting at the forefront (2h after ingestion) + diarrhea — rapid resolution (6–24h) — source: cold cuts + pastries + sandwiches left at room temperature + Bacillus cereus two distinct syndromes — emetic syndrome (overcooked, reheated rice — 1–5h) + diarrheal syndrome (meat + vegetables — 8–16h); ; Clostridium difficile (Clostridioides difficile): antibiotic-associated diarrhea + nosocomial infections — see specific fact sheet; ; Vibrio cholerae : rare in Canada — travelers + endemic areas (Africa + South Asia) — massive rice-water diarrhea + fulminant dehydration + mandatory national MDO
- Parasitic causes and general clinical presentation: Giardia lamblia (Giardia duodenalis): protozoan — the most common intestinal parasitic infection in Canada — source: untreated surface water (hiking in the mountains + campground water) + daycare centers (fecal-oral transmission among children) — incubation period: 1–3 weeks — clinical presentation: fatty diarrhea (steatorrhea) + excessive flatulence + abdominal cramps + no blood or fever — duration: weeks to months if untreated — diagnosis: Giardia fecal antigen (ELISA — sensitivity 94% %) or stool PCR — treatment: metronidazole 250 mg × 3/day × 5–7 days or tinidazole 2 g once daily (better compliance); ; Cryptosporidium parvum Intracellular protozoan — chlorine-resistant (swimming pools++ — outbreaks linked to water parks) — profuse watery diarrhea — self-limiting in immunocompetent individuals (5–10 days) → severe and prolonged in immunocompromised individuals (HIV CD4 <100 → diarrhée chronique dévastatrice) — diagnostic : pcr selles ou immunofluorescence traitement nitazoxanide 500 mg × 2 j 3jours (immunocompétent) pas de efficace chez l'immunodéprimé sévère (restauration immunitaire sous tar) ; Entamoeba histolyticaem Protozoal — rare in Canada — travelers + immigrants — amebic dysentery (bloody diarrhea + mucus) + amebic liver abscess — diagnosis: stool PCR + serology (liver abscess) — treatment: metronidazole + paromomycin (eradication of cystic forms); clinical presentation pointing to the cause: sudden onset ≤12–24h + predominant vomiting → food poisoning (preformed toxin — staphylococcus + B. cereus) + watery diarrhea + mild fever + no blood → viral (norovirus + rotavirus) or ETEC + watery-bloody diarrhea + high fever + intense abdominal pain → invasive bacteria (Campylobacter + Salmonella + Shigella) → stool culture + chronic greasy diarrhea without fever → Giardia → fecal antigen
Assessment of dehydration, treatment, and special situations
| Clinical situation | Evaluation and Diagnosis | Treatment and follow-up |
|---|---|---|
| Dehydration assessment and microbiological analysis Dehydration Scale — Coproculture — Indications |
Assessing the severity of dehydration is the most important clinical step in the management of acute dehydration—it determines the route and volume of rehydration; Assessment of dehydration in children (Clinical Dehydration Score—CDS or Gorelick scale): no dehydration: normal behavior + eyes not sunken + moist mucous membranes + tears present + skin turgor recovery time <2 sec + no skin fold — mild to moderate dehydration (3–7% of body weight lost): irritability or mild lethargy + slightly sunken eyes + dry mucous membranes + thirst + skin turgor recovery time (STR) 2–3 sec + mild skin fold → intensive oral rehydration — severe dehydration (>8% of body weight lost): lethargy or unconsciousness + very sunken eyes + very dry mucous membranes + tachycardia + hypotension + RRT >3 sec + persistent skin fold + anuria → urgent IV rehydration; Assessment of dehydration in adults: clinical signs: dry mucous membranes + intense thirst + tachycardia + orthostatic hypotension (>20 mmHg drop in systolic blood pressure upon standing) + oliguria + confusion (severe) + weight loss (objective if baseline weight is known); Laboratory workup: indicated if: moderate to severe dehydration + intractable vomiting + duration >7 days + extreme ages + comorbidities → electrolyte panel + creatinine + blood glucose + complete blood count; indications for microbiological testing (stool culture + stool parasitology): no routine testing in mild to moderate AGE in immunocompetent adults (presumed viral cause + spontaneous resolution) — testing indicated if: bloody diarrhea (dysentery) + fever ≥38.5°C + duration >7 days + recent travel (≤30 days) + contact with a known case of acute intestinal infection + suspected foodborne illness (≥2 cases in the same food source) + high-risk population (immunocompromised + pregnancy + extreme ages) + need for antibiotic therapy to be considered; contents of the microbiological workup: standard stool culture: Salmonella + Shigella + Campylobacter ± E. coli O157:H7 (specifically request if EHEC is suspected) + stool parasitology (OP — ova and parasites): 3 samples collected 24–48 hours apart if Giardia or Cryptosporidium is suspected + rapid fecal antigen tests: Giardia + Cryptosporidium (ELISA or immunochromatography — results in 30 min) + multiplex stool PCR (BioFire GI Panel or Luminex xTAG GI): simultaneous detection of 22 pathogens (viruses + bacteria + parasites) — higher sensitivity than conventional methods — indicated in immunocompromised patients + severe cases + complex epidemic situations + toxin C. difficile (GDH + toxins A/B): if diarrhea after recent antibiotic treatment ((8 weeks) or recent hospitalization + blood cultures: if high fever + signs of bacteremia + at-risk patient (elderly + sickle cell anemia + immunocompromised) | Criteria for hospitalization: severe dehydration (>8% of body weight) + inability to rehydrate orally (uncontrollable vomiting) + signs of sepsis (fever >39 °C + tachycardia + hypotension + confusion) + profuse bloody diarrhea + suspected EHEC (risk of HUS) + extreme ages (infants <3 months + frail elderly) + severe immunosuppression + decompensated comorbidities (heart failure + kidney failure + poorly controlled diabetes) + unfavorable social context (inability to rehydrate at home); additional tests if hospitalized: electrolyte panel + creatinine + complete blood count + CRP + blood cultures if fever + stool culture + multiplex PCR of stool + abdominal imaging if severe atypical pain (CT scan → rule out appendicitis + pseudomembranous colitis + peritonitis) |
| Rehydration — cornerstone of treatment Early IV rehydration and feeding |
Oral rehydration is the standard of care for acute dehydration in the vast majority of cases—it is as effective as IV rehydration for mild to moderate dehydration and reduces hospitalizations by 50% %; oral rehydration solutions (ORS): optimal composition according to the WHO: sodium 75 mmol/L + chloride 65 mmol/L + glucose 75 mmol/L + potassium 20 mmol/L + citrate 10 mmol/L → osmolarity 245 mOsm/L (WHO 2002 hypo-osmolar ORS — superior to the old hyperosmolar formula for reducing the duration of diarrhea) — products available in Quebec: Pedialyte (flavored + lollipops) + Gastrolyte + Lytren + homemade solutions not recommended (apple juice + sports drinks + salty broth → unsuitable electrolyte composition — Gatorade too sweet + not salty enough); oral rehydration technique in children (CPH — Canadian Paediatric Society guidelines): mild to moderate dehydration → ORS 50 mL/kg over 4 hours (rehydration phase) → then 10 mL/kg for each additional loose stool (maintenance phase) → administer in small, frequent amounts (5–10 mL every 5–10 min if vomiting) → Rapid progression if tolerated + resumption of normal diet (including dairy products) as soon as rehydration is established (do not prolong the liquid diet — strong evidence against prolonged restrictive «BRAT» diets) + ondansetron (Zofran): antiemetic — 1 single dose PO or sublingual (0.15–0.2 mg/kg — maximum 8 mg) → reduces vomiting + improves adherence to oral rehydration + reduces hospitalizations (2011 Cochrane meta-analysis) — recommended by the CPS if vomiting prevents oral rehydration — available over the counter in 4 mg tablets in Canada; IV rehydration (severe dehydration or failure of oral rehydration): bolus of 0.9% NaCl % (normal saline): 20 mL/kg IV over 15–30 min → repeat until blood volume is restored → then IV rehydration solution (Ringer’s Lactate or 0.9% NaCl % + KCl based on electrolyte levels) to correct the deficit within 4–6 hours → resume oral rehydration as soon as tolerated → do not administer hypotonic solutions (D5W + D10W) to infants (risk of hyponatremia) | Infant feeding in gastroenteritis — current recommendations: Resume normal feeding as soon as possible (as soon as the initial rehydration phase is completed — often within the first 4 hours) — prolonged restrictive diets (white rice + carrots + bananas) have not demonstrated any benefit and may prolong recovery → diet rich in complex carbohydrates + protein + avoid fatty and hyperosmolar foods in the first 24 hours (excess osmotic diarrhea) — breastfeeding: never interrupt breastfeeding — continue breastfeeding throughout the episode of gastroenteritis (protective factors + rehydration ensured) → supplement with ORS if signs of dehydration — cow's milk and dairy products: early resumption of dairy products is recommended (no clinically significant hypolactasia in viral gastroenteritis in immunocompetent children in developed countries — Cochrane data 2013 showing no benefit from milk exclusion) — exception: some infants develop transient lactose intolerance after severe gastroenteritis (rotavirus) → temporary lactose-free formula if symptoms persist; probiotics in gastroenteritis: Lactobacillus rhamnosus GG (Culturelle) + Saccharomyces boulardii (Florastor): Strongest data - meta-analyses (Guarino 2014 + Allen 2010 - Cochrane): reduction in diarrhea duration of 0.7-1 day + reduction in stool frequency on day 2 - modest but statistically significant effect - safe + well-tolerated → acceptable option in children → ESPGHAN 2014 recommendations: specific probiotics recommended as an adjunct to rehydration (not as a substitute) |
| Antibiotic therapy in bacterial gastroenteritis Targeted indications — Campylobacter — Shigella — Salmonella |
Antibiotic therapy is not systematically indicated for bacterial gastroenteritis (GEA) — the vast majority is self-limiting and resolves without antibiotics — inappropriate prescription promotes bacterial resistance and can worsen some infections (EHEC); principles for prescribing antibiotics in GEA: never prescribe empirically without serious clinical evaluation + indication must be justified by: clinical severity (high fever + significant bloody diarrhea + clear dysenteric syndrome) + at-risk patient population (immunocompromised + infants + elderly + sickle cell patients) + confirmed or highly suspected specific pathogen; absolute contraindications to antibiotics: confirmed or suspected EHEC O157:H7 (bloody diarrhea + epidemic + raw ground beef contact) → ANTIBIOTICS CONTRAINDICATED → increase risk of HUS by 17 (meta-analysis Wong 2000) → strict symptomatic treatment + monitoring CBC + kidney function + bilirubin; indications and choice of antibiotics by pathogen: Campylobacter jejuni : azithromycin 500 mg/day × 3 days (first-line treatment — fluoroquinolone resistance >20% in Canada → ciprofloxacin as second-line treatment only if susceptibility testing is favorable) — indication: clinical severity + immunosuppression + bacteremia + Shigella azithromycin 500 mg/day × 3 days or ciprofloxacin 500 mg × 2/day × 3 days (according to antibiogram) — indication: always treat (bacillary dysentery + highly contagious + intrinsic severity) + Salmonella non-typhoidal: treatment not routinely recommended (prolongs fecal excretion) - indication: bacteremia + risk of systemic complications (infants) <3 mois + personnes âgées drépanocytaires prothèses vasculaires vih) → ciprofloxacine 500 mg × 2 j 7–14 joursou ceftriaxone iv si bactériémie grave diarrhée du voyageur (etec) : rifaximine 200 3 (non absorbée — traitement local luminal pasde résistances croisées avec les autres antibiotiques systémiques) azithromycine 1 g (formes invasives fébrile voyageur) Giardiaem : metronidazole 250 mg 3 times daily for 5–7 days or tinidazole 2 g as a single dose (preferred—single dose + efficacy ≥95% %) + E. histolytica metronidazole 750 mg × 3/day × 10 days + paromomycin 25–35 mg/kg/day × 7 days (eradication of cystic forms) + Cryptosporidium (immunocompetent): nitazoxanide 500 mg × 2/day × 3 days (moderate efficacy — not reimbursed by RAMQ — special access) | Symptomatic adjuvant treatments: loperamide (Imodium): intestinal motility inhibitor — slows transit + reduces secretions + increases anal sphincter tone — adult: 4 mg initially + 2 mg after each loose stool (maximum 16 mg/day) — demonstrated efficacy in reducing diarrhea duration by 1–2 days — absolute contraindications: bloody or dysenteric diarrhea (risk of toxic megacolon) + high fever + suspected EHEC + child <2 years — avoid use if invasive infectious cause suspected (Shigella + C. difficile) → risk of bacteremia and complications; racecadotril (Tiorfan — enkephalinase inhibitor): reduces intestinal secretion without inhibiting peristalsis — child +++ (baby 1.5 mg/kg × 3/day — 10 mg tablets) + adult (100 mg × 3/day) — modest efficacy but better safety profile than loperamide in pediatrics — availability in Canada variable; diosmectite (Smecta): adsorbent clay — reduces diarrhea duration by 0.5–1 day — safe + well-tolerated (including infants) — useful adjunct to oral rehydration; hygiene and prevention of transmission: hand washing with soap and water × 20 seconds (CDC): most effective measure + alcohol-based solution INSUFFICIENT for norovirus and C. difficile → Emphasize soap and water — exclusion from school/daycare/work: up to 48 hours after vomiting and diarrhea resolve (norovirus is particularly contagious) — surface disinfection: sodium hypochlorite (bleach) at 1,000 ppm (1:10 dilution) → effective against norovirus — alcohol-based hand sanitizers: insufficient |
| Traveler's diarrhea ETEC - prevention - rifaximin - azithromycin |
Traveler's diarrhea (TD) is the most common illness among international travelers—it affects 20–60% of travelers to high-risk regions (South Asia, sub-Saharan Africa, Latin America, and the Middle East); causative agents: ETEC (E. coli (enterotoxigenic): 40–60 % of DV in tropical countries + Campylobacter Southeast Asia++ Salmonella + Shigella + norovirus + rotavirus + Giardia + Cryptosporidium (water) + emerging agents: E. coli enteroaggregative (EAEC) + E. coli Enteropathogenic (EPEC); clinical presentation: profuse watery diarrhea + abdominal cramps + nausea + sudden onset within 2 weeks of arrival in a high-risk country — mild fever possible — duration: 1–5 days if uncomplicated ETEC — severe forms (febrile dysentery) → Campylobacter + Shigella + amoebiasis; prevention of traveler’s diarrhea: food safety rules («Boil it, cook it, peel it, or forget it»): drink only bottled or boiled water + avoid ice cubes + salads + raw vegetables + unpeeled fruits + raw fish and shellfish + street food (insufficient heat) → partial effectiveness: 30–50% reduction in risk — oral cholera vaccine (Dukoral): contains cholera subunit B → partial cross-protection against ETEC (same subunit B) → modest reduction (25–50% %) in ETEC-related severe disease → recommended for high-risk travelers (immunocompromised + IBD) → case-by-case indication + prophylactic rifaximin: 200 mg/day × duration of stay → 77% reduction in the risk of ETEC-related severe illness (clinical trials) → not routinely recommended (risk of resistance + cost) → option for high-risk travelers (immunocompromised + recent surgery + IBD) + probiotics: Saccharomyces boulardii → meta-analyses: modest reduction (approximately 15–25% %) in the risk of DV → safe + acceptable option | Traveler's diarrhea treatment: 1st line treatment (mild to moderate diarrhea without fever or blood): rifaximin 200 mg 3 times/day for 3 days (not absorbed → luminal treatment → no effect on invasive bacteria → to be reserved for non-febrile, non-bloody diarrhea → effective against ETEC++); or loperamide alone (symptomatic + reduced duration); 2nd line treatment (moderate to severe diarrhea with fever and/or blood): azithromycin 1 g PO single dose or 500 mg/day for 3 days → covers Campylobacter + Shigella + Salmonella + ETEC → 1st line in Southeast Asia (fluoroquinolone resistance) Campylobacter (nearly universal) + ciprofloxacin 500 mg × 2/day × 3 days → alternative if azithromycin unavailable → to avoid in Southeast Asia (Campylobacter resistance) → effective for E. coli + Salmonella + Shigella In Latin America + Africa; self-medication recommended for travelers: pre-prescribe azithromycin + loperamide (for use in case of severe traveler's diarrhea during the trip) → explain criteria for use and situations requiring medical consultation (high fever + blood + duration >3 days + severe dehydration); prolonged traveler's diarrhea (>14 days): prioritize suspicion of parasites: Giardia + Cryptosporidium + Cyclospora cayetanensis (Asia + Americas) + Entamoeba histolytica + Post-infectious SIBO + post-infectious IBS → stool parasitology × 3 + fecal antigens + travel medicine or infectious disease consultation |
| Gastroenteritis in Children — Pediatric Specifics SRO — ondansetron — rotavirus vaccine —HUS |
Acute kidney injury in children has significant clinical and therapeutic characteristics—dehydration is the main complication and can quickly become severe in infants; Risk of dehydration by age: infants <6 months: highest risk (low fluid reserves + large body surface area + inability to express thirst + total dependence on caregivers) → lower hospitalization threshold — children 6 months–5 years: significant risk — rotavirus → severe dehydration prior to vaccination — children >5 years and adolescents: lower risk — presentation similar to adults; rotavirus and vaccination: prior to the vaccination program (2011 in Quebec): leading cause of hospitalization for acute gastroenteritis in children <2 years old — since the Quebec program: 85–90% reduction in rotavirus hospitalizations — oral vaccine (Rotarix 2 doses or RotaTeq 3 doses): 1st dose as early as 6 weeks — do not exceed 14 weeks for the 1st dose (risk of intussusception if started too late) — free under the Quebec vaccination program; post-EHEC hemolytic uremic syndrome (HUS): a serious complication occurring 2–14 days after EHEC colitis — triad: microangiopathic hemolytic anemia + thrombocytopenia + acute renal failure — mechanism: shigatoxins → endothelial damage to glomerular and cerebral capillaries → MAT — incidence: 5–15 per 1,000 children infected with EHEC O157:H7 — mortality: 1–5% (decreasing) — sequelae: chronic kidney disease in 30% — treatment: supportive care (dialysis if necessary) + eculizumab (anti-C5 — complement inhibitor) in severe cases with neurological involvement or refractory HUS (KDIGO 2020 recommendations) — no antibiotics + no antiemetics; vomiting in pediatric AHF: ondansetron (Zofran): 1 oral or sublingual dose (0.15 mg/kg — max 4 mg <15 kg + 8 mg ≥15 kg) → SCP: recommended to allow for oral rehydration and avoid hospitalization (2011 Cochrane meta-analysis) → 54% reduction in hospitalization rate at 1–3 days vs. placebo — metoclopramide: not recommended in children (extrapyramidal effects) — domperidone: efficacy not demonstrated in pediatric acute gastroenteritis | Intestinal intussusception — a key diagnosis in children: critical differential diagnosis of acute abdominal pain in infants aged 3 months to 3 years — clinical presentation: intermittent abdominal pain with pain-free intervals + pallor + hypotonia + vomiting + «redberry jelly» stools (blood + mucus — late) — ATYPICAL: may mimic acute abdominal pain with lethargy and vomiting without obvious abdominal signs → any child with disproportionate lethargy + paroxysmal pain + vomiting → urgent abdominal ultrasound ( «target» or «rosette» image + mass in the right iliac fossa) → hydrostatic reduction via enema under fluoroscopic or ultrasound guidance (success rate 85% %) → surgery if unsuccessful or perforation; other differential diagnoses of acute abdominal pain in children: acute appendicitis (right iliac fossa pain + fever + guarding + CBC + elevated CRP + CT or ultrasound) + meningitis (fever + neck stiffness + vomiting + photophobia) + strangulated inguinal hernia + diabetic ketoacidosis (initial symptoms may be gastrointestinal → blood glucose + ketone bodies) + Henoch-Schönlein purpura + poisoning (acetaminophen + accidental ingestion) → systematically consider these diagnoses in the face of any atypical gastrointestinal presentation in children; prevention of gastroenteritis in group settings (daycare centers + schools): hygiene rules: mandatory handwashing with soap + after using the restroom + before and after meals → exclusion: up to 48 hours after vomiting and diarrhea have resolved → cleaning and disinfection with bleach of contact surfaces (tables + doorknobs + toys) |
ℹ️
Antibiotics are contraindicated in bloody diarrhea if E. coli O157:H7 (EHEC) is suspected: In the event of bloody diarrhea after consuming undercooked ground beef or untreated water—especially in a child—hemolytic uremic syndrome (HUS) should be suspected. Antibiotics, by lysing bacteria, massively release shiga toxins and increase the risk of HUS by 17-fold. The rule is not to prescribe antibiotics, not to administer anti-motility agents (loperamide), and to refer the patient to the emergency department for monitoring of renal function, complete blood count, and platelets.
Situations requiring urgent medical assessment
Infant < 3 months with vomiting + diarrhea + fever or hypothermia + lethargy or bulging fontanelle urgent hospitalization + complete infectious workup + IV rehydration + rule out meningitis and neonatal sepsis.
Bloody diarrhea + paleness + anuria + edema + confusion in a child who consumed raw ground beef → SHU post-EHEC → pediatric emergency → CBC + platelets + creatinine + LDH + stool culture EHEC → no antibiotics + no loperamide → dialysis if necessary.
Severe dehydration: lethargy + sunken eyes + persistent skin turgor + tachycardia + hypotension + anuria → Emergency IV rehydration → 0.9% NaCl %, 20 mL/kg IV bolus → repeat until stabilized → electrolyte panel + creatinine.
Diarrhea + high fever + severe abdominal pain + abdominal wall rigidity Intestinal perforation or peritonitis → urgent abdominal CT scan + emergency surgery + broad-spectrum IV antibiotics.
Consult at Clinique Omicron
Clinique Omicron physicians evaluate acute gastroenteritis in children and adults, including assessing the degree of dehydration, recommending oral or hospital rehydration, prescribing targeted antibiotics based on the pathogen, and monitoring prolonged cases requiring microbiological investigation. Telemedicine is available for the initial evaluation of mild to moderate cases. These services are accessible at several service points in Quebec. To book an appointment, visit cliniqueomicron.ca.
The content of this page is provided for informational purposes only and does not substitute the advice of a doctor or pediatrician. Any episode of bloody diarrhea, severe dehydration, or uncontrollable vomiting should be promptly evaluated by a healthcare professional.
Omicron Clinic
Need to consult a doctor?
Treatment within 24-48 hours. In-clinic or telemedicine, anywhere in Quebec.
Insurance receipts. 7j/7. No family doctor required.