Diarrhea and vomiting: field triage, ORS, and when antibiotics help

Gastrointestinal illness kills through dehydration faster than through any direct effect of the germ itself. The single most important intervention — oral rehydration solution — costs almost nothing, works in 90% of cases without any medication, and is something you can mix from household ingredients. Antibiotics, by contrast, are indicated for a narrow set of presentations and actively harmful in others. Getting the order right — fluids first, antibiotics rarely, evacuation when criteria are met — is the whole framework.

Educational use only

This page provides general educational information for emergency preparedness scenarios when professional medical care is unavailable. It is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of a qualified healthcare provider. Use this information at your own risk.

Before you start - Skills: Basic patient observation — assess mental status, count breaths, observe skin and mucous membranes. No clinical training required for initial triage. - Materials: WHO ORS ingredients (salt, sugar, baking soda or trisodium citrate) per dehydration.md; oral syringe or teaspoon for vomiting patients; thermometer; nitrile gloves; bleach solution (1:10 dilution = 5,000 ppm chlorine) for contact surfaces per CDC norovirus disinfection guidelines. - Time: Initial syndrome classification: 5 minutes. ORS preparation: 3 minutes per liter. Reassessment interval during active illness: every 4–6 hours. - Conditions: Patient is conscious and able to swallow. If confused, unresponsive, or cannot swallow at all, do not attempt oral fluids — go directly to evacuation or rectal rehydration (see dehydration.md) while arranging transport. - Antibiotic thresholds: Empiric antibiotic criteria per IDSA 2017 Infectious Diarrhea Guideline (Shane et al., Clinical Infectious Diseases 65:e45-e80, 2017) — dysentery + fever, moderate-to-severe traveler's diarrhea, or immunocompromised status.

Action block

Do this first: Mix a 1-liter (34 oz) batch of WHO ORS and get the patient drinking it — one sip every 1–2 minutes if vomiting, unrestricted if tolerating fluids (active time: 5 minutes). Time required: Active: 5 minutes to mix ORS; 4 hours per WHO rehydration plan; ongoing reassessment every 4–6 hours during illness. Cost range: Inexpensive for DIY ORS (salt, sugar, baking soda); affordable for commercial ORS sachets and a digital thermometer. Skill level: Beginner for ORS administration and syndrome classification; intermediate for recognizing sepsis and managing pediatric cases; advanced/expert for empiric antibiotic selection. Tools and supplies: Tools: measuring container (1 L / 34 oz), teaspoon or kitchen scale, oral syringe for vomiting patients. Supplies: table salt, white sugar, baking soda, clean treated water; thermometer; nitrile gloves; bleach; stockpiled ciprofloxacin, azithromycin, and oral vancomycin per stockpiling. Safety warnings: See Red flags: when to evacuate or escalate below — bloody stool with fever, infant illness, suspected hemolytic uremic syndrome, and qSOFA-positive sepsis are evacuation emergencies.

Why GI illness is dangerous in austere settings

The risk equation for gastrointestinal illness shifts dramatically when you lose access to clinical care. Three specific dangers compound each other:

Dehydration outpaces perception. A healthy adult can lose 1 liter of fluid per hour during severe gastroenteritis. Mental status changes — the clearest sign of serious dehydration — arrive late, when reserves are already critically depleted. By the time someone "looks dry," they may have lost 6–10% of their body weight in fluid. Children deteriorate faster. Elders have smaller reserves and diminished thirst response.

Outbreak spread is rapid in close quarters. Norovirus is transmissible from aerosolized vomit at concentrations as low as 18 viral particles. One sick person in a four-person household, sharing a bathroom and kitchen, can infect the entire group within 48 hours without deliberate containment. Infectious diarrhea in a group setting is not an individual medical problem — it is a household emergency that demands immediate isolation.

Antibiotic missteps cause harm. The most dangerous error in managing bloody diarrhea is reflex antibiotic use when Shiga toxin-producing Escherichia coli (STEC, also called E. coli O157:H7) is the cause. Fluoroquinolones and other antibiotics increase Shiga toxin release, raising the risk of hemolytic uremic syndrome (HUS) — a life-threatening kidney failure syndrome — in children by more than 17-fold per multivariate analysis. Knowing when not to use antibiotics is as important as knowing when to use them.

Stool pattern and likely pathogen class

You cannot confirm the organism without a lab. What you can do is classify by clinical pattern — the combination of stool character, fever, timing, and exposure narrows the likely cause enough to guide action.

Pattern Timing and context Most likely class Action
Watery, no blood, no fever; multiple people sick at once Onset 24–48 hr after shared exposure Viral (norovirus, rotavirus) ORS only. No antibiotics. Isolate.
Bloody or mucoid stool, fever ≥100.4°F (38°C), abdominal cramps Hours to a few days after exposure Bacterial (Shigella, Campylobacter, Salmonella) ORS + consider empiric antibiotics per criteria below.
Persistent watery diarrhea >7 days; foamy, greasy, or foul-smelling stool; significant weight loss; recent untreated water exposure Onset days to weeks after exposure Parasitic (Giardia, Cryptosporidium) ORS + specific antiparasitic after 7+ days.
Vomiting > diarrhea; multiple people ill within 6 hours of a shared meal; no fever Onset 30 minutes–6 hours Preformed toxin (Staph aureus, Bacillus cereus) ORS + anti-emetic if available. No antibiotics. Supportive only.
Bloody stool (may have no fever), child with recent raw beef or unpasteurized dairy exposure Sudden onset STEC / E. coli O157:H7 ORS only. DO NOT START ANTIBIOTICS. Evacuate if HUS signs appear.
Watery, frequent, possibly bloody; started during or within 2 months of antibiotic use Recent clindamycin, fluoroquinolone, or cephalosporin course Clostridioides difficile Stop the inciting antibiotic. Oral vancomycin. Isolate with soap-and-water handwash.

Sources: CDC Norovirus; CDC E. coli / STEC clinical guidance; IDSA Infectious Diarrhea Guideline 2017 (Shane et al., CID 65:e45-e80).

Dehydration assessment and ORS dosing

The full WHO ORS formula, the DIY recipe from household ingredients, and the dehydration severity assessment table live in dehydration assessment and rehydration. Read that page before a crisis, not during one. What follows here is the GI-illness-specific dosing protocol.

Dosing for active GI illness

Adults: - Per loose stool: 200–400 mL (about 1–2 cups) of ORS to replace ongoing losses, in addition to the baseline rehydration plan. - Per WHO guidance, an adult who has not yet developed severe dehydration should receive 75 mL/kg ORS over 4 hours (Plan B). That is roughly 4–5 liters for a 60 kg (132 lb) adult.

Children (mild to moderate dehydration): - WHO Plan B: 75 mL/kg over 4 hours. - Example: a 15 kg (33 lb) child receives 1,125 mL (about 38 oz) over 4 hours.

Vomiting patients: - Use an oral syringe or teaspoon. Give 5 mL (1 teaspoon) every 1–2 minutes. This volume is below the vomiting threshold for most patients. - If the patient cannot keep down a single 5 mL sip after a 30-minute trial, oral rehydration has failed — escalate to rectal rehydration per dehydration.md or evacuate. - Continue ORS even if mild vomiting continues. Small sips kept down accumulate.

Dehydration severity — act before the late signs appear

Sign Mild (3–5% BW loss) Moderate (6–9% BW loss) Severe (≥10% BW loss)
Thirst Yes Yes, intense May be absent — patient too weak
Urine Dark yellow, reduced Very dark, minimal None in 8+ hours
Eyes Normal Slightly sunken Deeply sunken, no tears
Skin turgor Normal (tent resolves <2 sec) Slow (tent 2–3 sec) Very slow (>3 sec)
Mental status Alert Irritable or lethargic Confused, limp, unresponsive
Pulse Normal Rapid Rapid and weak

Severe dehydration = hypovolemic shock. Do not attempt oral fluids in a confused, limp, or unresponsive patient. Begin rectal rehydration (proctoclysis) per dehydration.md and evacuate immediately.

For pediatric dehydration thresholds including the sunken fontanelle sign in infants and per-age wet-diaper baselines, see infant care.

Viral diarrhea: supportive only

Viral gastroenteritis — primarily norovirus and rotavirus — accounts for the majority of acute GI illness worldwide. Both are self-limiting in immunocompetent individuals.

Norovirus: incubation 12–48 hours; duration 1–3 days. Profuse watery diarrhea and vomiting, often sudden in onset. Highly contagious — transmissible by fecal-oral route, contaminated surfaces, and aerosolized vomit. No antiviral treatment exists.

Rotavirus: incubation 2 days; duration 3–8 days. More common in children under 5. Watery diarrhea, vomiting, and fever. A vaccine exists (Rotarix, RotaTeq); stockpile vaccination records for pediatric household members.

Treatment: 1. Start ORS immediately. This is the only treatment that matters. 2. Do not give antibiotics. They have no effect on viruses and will disrupt gut flora. 3. Do not give loperamide (Imodium) if there is any blood in stool, fever above 101°F (38.3°C), or severe dehydration — it slows pathogen clearance and can cause toxic megacolon in bacterial dysentery.

Anti-emetics (optional adjunct): Ondansetron (Zofran) reduces vomiting enough to allow ORS retention. If available:

  • Adults: 4 mg orally dissolving tablet (ODT). Repeat 4–8 mg in 4–8 hours if needed.
  • Children: 0.15 mg/kg per dose, max 4 mg per dose, per AAP guidance.
  • Use only if vomiting is preventing ORS retention. Ondansetron is not a substitute for rehydration — it is a tool to make rehydration possible.

For isolation procedures during a viral outbreak affecting multiple household members, see pandemic preparedness.

Bacterial dysentery: when empiric antibiotics are justified

Dysentery is diarrhea with visible blood and mucus, usually accompanied by fever and abdominal cramps. It indicates bacterial invasion of the colon lining. The most common causes are Shigella, Campylobacter, and non-typhoidal Salmonella.

IDSA criteria for empiric antibiotic use

Per the 2017 IDSA Infectious Diarrhea Guideline (Shane et al.), start empiric antibiotics when any of the following are present in an immunocompetent adult:

  • Bloody diarrhea (dysentery) with fever and abdominal cramps or tenesmus
  • Moderate-to-severe traveler's diarrhea (incapacitating, >4 stools/day, or any systemic symptoms)
  • Immunocompromised patient with any infectious diarrhea
  • Signs of sepsis (see qSOFA criteria in wound infection)

Do NOT start empiric antibiotics for: - Mild watery diarrhea without fever or blood — supportive care only - Suspected STEC / E. coli O157:H7 (see next section) - Children who just ate rare hamburger or unpasteurized dairy and have bloody diarrhea without fever — this is STEC until proven otherwise

Empiric antibiotic selection

Patient First choice Alternative
Adult (non-pregnant, non-quinolone-resistant region) Ciprofloxacin 500 mg twice daily × 3 days Azithromycin 500 mg daily × 3 days
Pregnant adult Azithromycin 500 mg daily × 3 days (Avoid fluoroquinolones in pregnancy)
Pediatric Azithromycin 10 mg/kg/day × 3 days (max 500 mg/day) (Avoid fluoroquinolones in children unless no alternative)
Traveler's diarrhea, single-dose option Ciprofloxacin 750 mg once OR azithromycin 1 g once Rifaximin 200 mg three times daily × 3 days if non-invasive
Quinolone-resistant region (South/Southeast Asia, parts of South America) Azithromycin 500 mg daily × 3 days —

Source: IDSA 2017 Infectious Diarrhea Guideline (Shane et al., CID 65:e45-e80).

Field note

Azithromycin covers both Campylobacter (increasingly fluoroquinolone-resistant globally) and Shigella. If your stockpile has azithromycin but not ciprofloxacin, azithromycin 500 mg daily × 3 days is a reasonable first empiric choice for adult dysentery in most settings. Don't wait for a full assessment before starting ORS — antibiotics follow, fluids lead.

Signs antibiotics are working (reassess at 48 hours)

  • Fever trending down
  • Frequency of bloody stools decreasing
  • Patient more alert, less painful
  • Abdominal tenderness reducing

If the patient is not improving after 48 hours of appropriate antibiotics, re-examine the situation. Possibilities include: wrong organism, antimicrobial resistance, unrecognized C. diff from a prior antibiotic course, or an abdominal complication (perforation, abscess) that requires surgical evaluation.

The STEC exception: never start antibiotics

Do NOT give antibiotics for suspected STEC / E. coli O157:H7

Suspect STEC when: bloody diarrhea in a child (especially without fever, or with low-grade fever only) after eating raw or undercooked beef, unpasteurized juice, raw milk, or produce from a farm; or during a known community outbreak.

Why antibiotics are contraindicated: Fluoroquinolones and other antibiotics increase expression of the stx2 gene in STEC, triggering massive Shiga toxin release. This raises the risk of hemolytic uremic syndrome (HUS) in children by more than 17-fold in some studies. HUS causes kidney failure, hemolytic anemia, and thrombocytopenia — a triad that kills or causes permanent kidney damage without hospital-level care.

Treatment: ORS and supportive care only. Early IV fluids (within the first 4 days) reduce the risk of renal failure.

Evacuate immediately if you see the HUS triad in a child: bloody diarrhea + decreased urine output + pallor or bruising. These indicate kidney failure in progress.

Parasitic diarrhea: the persistent cases

Parasitic GI illness announces itself by refusing to resolve. When diarrhea persists beyond 7 days, especially with exposure to untreated or inadequately filtered water, think Giardia or Cryptosporidium.

Giardia

Suspect when: foamy, greasy, foul-smelling (sulfurous) diarrhea with fatigue, weight loss, bloating; onset 1–3 weeks after untreated surface-water exposure; may persist for months without treatment.

Treatment: - Tinidazole 2 g single oral dose (preferred — highest cure rate, ~90%, fewer side effects). Take with food to reduce nausea. - Metronidazole 250 mg three times daily × 5–7 days if tinidazole unavailable (cure rate 85–90%; more GI side effects and alcohol interaction). - Pediatric: tinidazole 50 mg/kg single dose (max 2 g); metronidazole 5 mg/kg three times daily × 5 days.

Cryptosporidium

Suspect when: profuse watery diarrhea lasting 1–4 weeks; immunocompromised patients at highest risk (HIV, chemotherapy, transplant); exposure to contaminated water, animal feces, or daycare settings.

Treatment in immunocompetent patients: - Nitazoxanide 500 mg twice daily × 3 days (adults and patients ≥12 years). FDA-approved for cryptosporidiosis; clinical cure rate 72–88%. - Supportive care (ORS) is the mainstay. Nitazoxanide accelerates recovery. - Immunocompromised patients: nitazoxanide has not shown superiority over placebo in HIV-infected patients. Supportive care plus evaluation for immune reconstitution is the primary management. Evacuate to medical care.

Water is the source — filter it correctly

The most important prevention measure is adequate water filtration. Both Giardia and Cryptosporidium cysts are too small for standard ceramic filters rated only for bacteria. You need:

  • Absolute pore size of 1 µm (0.001 mm) or smaller per CDC guidance — 0.2 µm absolute (the spec on most field hollow-fiber filters) provides additional margin and also captures most bacteria, OR
  • NSF P231 or NSF P248 certification (tests removal of protozoa including Cryptosporidium to ≥99.9%)

Chemical disinfection (bleach, iodine) is unreliable against Cryptosporidium at normal doses. Boiling is effective — bring to a rolling boil for 1 minute (3 minutes above 6,500 ft / 2,000 m elevation).

For filter specifications and comparison by method, see water filtration.

Toxin-mediated illness: onset under 6 hours

Preformed toxin illness is not an infection — it is poisoning from a toxin already present in food before you ate it. Antibiotics are useless and should not be given.

Staphylococcus aureus enterotoxin: onset 1–6 hours after eating improperly held foods (egg salad, deli meats, cream pastries held at room temperature). Symptoms: sudden severe vomiting > diarrhea, no fever or low-grade fever, abdominal cramping. Multiple people eating the same food become ill together within the same short window. Self-limited: most cases resolve in 24–48 hours.

Bacillus cereus (emetic type): onset 30 minutes–6 hours from starchy foods left at room temperature — rice is the classic culprit, but pasta, potatoes, and other starches also support growth. Severe vomiting, minimal diarrhea, rapid resolution (usually 24 hours). There is also a diarrheal type of B. cereus with a longer incubation (6–15 hours) and more diarrhea — both are self-limiting.

Treatment for both: 1. ORS — replace fluid losses from vomiting and diarrhea. 2. Anti-emetic (ondansetron 4 mg adult ODT) if available and vomiting is preventing ORS retention. 3. No antibiotics. 4. Identify and discard the contaminated food.

The underlying danger zone for foodborne illness is holding cooked food between 40°F and 140°F (4°C and 60°C) for more than 2 hours. For storage rules that prevent toxin-mediated illness before it starts, see food storage.

C. difficile suspicion: a special case

C. difficile requires a completely different protocol

Clostridioides difficile (C. diff) is not a typical foodborne or waterborne illness — it is a disruption of the gut microbiome, almost always triggered by prior antibiotic use. The antibiotics most likely to trigger C. diff are clindamycin, fluoroquinolones (including ciprofloxacin), and cephalosporins, though any antibiotic can cause it. Onset is typically during the antibiotic course or within 2 months of completing one.

Recognizing C. diff

  • Watery diarrhea, often very frequent (4–8+ times per day)
  • Cramping abdominal pain, particularly lower quadrant
  • Fever may be mild or absent in mild cases; high fever in severe cases
  • Stool may be bloody in severe colitis
  • The history of recent antibiotic use is the critical clue

Treatment

  1. Stop the inciting antibiotic immediately. This is the first and most urgent action. If the antibiotic was being used to treat another infection, that problem is secondary — C. diff is now the primary threat.

  2. Start oral vancomycin 125 mg four times daily (every 6 hours) × 10 days. This is the current standard of care per the 2021 IDSA/SHEA guideline update. Oral vancomycin is NOT the same as IV vancomycin — the oral form stays in the gut where it is needed; IV vancomycin does not reach therapeutic gut concentrations and does not treat C. diff.

  3. Fidaxomicin 200 mg twice daily × 10 days is preferred by the 2021 IDSA/SHEA guideline if available (lower recurrence rate than vancomycin), but oral vancomycin is widely available and appropriate for initial C. diff in a preparedness stockpile.

  4. Isolation protocol — this is non-negotiable. C. diff spores survive on surfaces for months and are NOT killed by alcohol-based hand sanitizer. Soap-and-water handwash is mandatory for anyone entering or leaving the sick room. Surfaces must be decontaminated with a 1:10 dilution of household bleach (5,000 ppm) and allowed to remain wet for at least 5 minutes.

  5. Dedicate a toilet if at all possible. C. diff spores are shed in enormous quantities in stool and can colonize any surface they contact.

When to evacuate for C. diff

  • Fever above 101.3°F (38.5°C) with abdominal distension and reduced bowel sounds — fulminant colitis
  • Worsening abdominal pain despite starting oral vancomycin
  • Sepsis features: altered mental status, rapid breathing, low blood pressure (qSOFA ≥2, see infection.md)
  • Pregnancy
  • Visible blood in large volume

Red flags: when to evacuate or escalate

Escalate to higher-tier care or treat as an emergency when any of the following are present:

Red flag Urgency Why
Blood in stool with fever ≥101.3°F (38.5°C) Urgent Dysentery with systemic response — antibiotics needed, may fail
Lethargy, confusion, or altered mental status Emergency Severe dehydration or sepsis
No urine output for 8+ hours Urgent Severe dehydration; approaching hypovolemic shock
Sunken eyes, no tears, skin tent >3 seconds Urgent Clinical severe dehydration — oral route may be insufficient
Fever ≥103°F (39.4°C) sustained Urgent Bacteremia possible
qSOFA ≥2 (altered mental status + RR ≥22/min + SBP ≤100 mmHg) Emergency Probable sepsis — evacuate now
Infant under 6 months with any diarrhea or vomiting Urgent Reserves are tiny; deterioration is rapid; see infant care
Pregnant patient with any dysentery or high fever Urgent Fetal risk from bacteremia, dehydration, and some antibiotics
Bloody diarrhea + decreased urine + pallor + bruising in a child Emergency Suspected HUS — kidney failure in progress; evacuate immediately
Symptoms continuing beyond 14 days despite supportive care Non-urgent escalation Parasitic cause likely; specific treatment needed
Immunocompromised patient with any persistent diarrhea Urgent Sepsis threshold is lower; organisms less easily cleared

For sepsis recognition using qSOFA and shock signs, see wound infection and sepsis.

Outbreak control: isolation and decontamination

One sick person in a household is a case. Two is an outbreak. The window to prevent spread is the first 4–6 hours. Once a second person becomes ill, the pathogen is already in the environment.

Immediate isolation steps

  1. Move the sick person to a single room if possible. Assign them one cup, one towel, and one blanket. Label them.

  2. Designate a single caregiver if possible. Rotation of multiple caregivers multiplies the exposure surface.

  3. The caregiver wears nitrile gloves when handling the patient, linens, or waste. Wear a mask if the patient is vomiting — norovirus spreads via aerosolized vomit.

  4. Handwash with soap and water after every contact with the patient or their environment. This is not optional. Alcohol-based hand sanitizer has partial efficacy against norovirus and zero efficacy against C. diff spores. Use at least 20 seconds of vigorous scrubbing.

  5. If a dedicated toilet is not possible, the sick person should use a dedicated bucket with a lid. Dispose of waste carefully, avoid splashing, and bleach the bucket after each use.

Surface decontamination

Mix 1 part household bleach (5.25% sodium hypochlorite) to 9 parts water = 1:10 dilution = approximately 5,000 ppm chlorine. This concentration is effective against norovirus, rotavirus, and C. diff spores.

Apply to: - Toilet (inside bowl, seat, handle, surrounding floor) - Sink faucets and handles - Doorknobs, light switches, and any surface the patient touches - Any surface contaminated by vomit or stool

Allow the bleach solution to remain wet on surfaces for at least 5 minutes before wiping. Fresh solution only — bleach degrades rapidly; mix a new batch every 24 hours.

Bedding and clothing

Vomit- or stool-contaminated laundry should be machine-washed at the highest temperature the fabric tolerates, then machine-dried on high heat. Wear gloves when handling soiled laundry. Do not shake contaminated items — this aerosolizes particles.

For comprehensive handwashing technique, contact isolation procedures, and household hygiene rules, see field hygiene and pandemic preparedness.

Common mistakes that get people killed

These are the errors that turn a manageable GI illness into a household emergency. Recognize them before you are in the situation.

Withholding ORS because "they're not that dry yet." Dehydration kills on a timeline. A child who vomited three times in two hours and has had no fluid intake is already losing ground. The time to start ORS is at the first symptom — not when sunken eyes appear. Dehydration kills before the organism does.

Giving loperamide (Imodium) with blood in the stool or fever. Loperamide slows gut motility. In bacterial dysentery, slowing the gut retains toxins and pathogens in contact with the intestinal wall longer. In STEC infection, it may increase Shiga toxin absorption. Do not use loperamide if there is any blood in the stool or any fever above 101°F (38.3°C).

Starting empiric antibiotics when STEC is the likely cause. If a child has sudden bloody diarrhea after eating undercooked hamburger and has no fever, the most dangerous thing you can do is open the ciprofloxacin. STEC is the working diagnosis until proven otherwise. Antibiotics in STEC raise HUS risk more than 17-fold.

Continuing the inciting antibiotic when C. diff is suspected. The moment you think C. diff — recent antibiotic use, frequent watery diarrhea, cramping — stop the antibiotic that may be causing it. The ongoing antibiotic fuels C. diff by continuing to suppress the gut flora that compete with it. Stopping the antibiotic is the first treatment step, not something to consider after trying other things.

Using alcohol hand sanitizer when C. diff or norovirus is present. Alcohol gel is partially effective against norovirus and completely ineffective against C. diff spores. In a contaminated environment, alcohol gel creates a false sense of clean. Use soap and water. Running water is the key mechanical step — the friction and rinsing remove pathogens that alcohol gel cannot inactivate.

Forgetting to isolate. Norovirus can survive on surfaces for days to weeks. One vomiting episode in a shared bathroom leaves active virus on every surface a hand touches. Without immediate isolation and bleach decontamination of the bathroom, the rest of the household is almost certain to become ill within 24–48 hours. An outbreak in four people who are all ill simultaneously is exponentially harder to manage than one ill person who is isolated.

Stopping ORS the moment symptoms improve. Diarrheal illness frequently produces a period of apparent improvement followed by relapse, especially in children. Continue ORS for at least 12–24 hours after the last loose stool. Reintroduce solid foods gradually — bland, low-fat, low-fiber foods first (rice, toast, bananas, broth). The gut lining needs time to recover.

Teach your family

Five rules that every household member old enough to understand should know before an illness happens:

  1. ORS first, always. If someone has diarrhea or is vomiting, the first action is to mix and start ORS. Not "wait and see." Not "rest first." Fluids now.

  2. No Imodium if there is blood or fever. When in doubt, skip it.

  3. Wake the responsible adult immediately if: blood appears in stool or vomit; the sick person cannot keep any liquid down for more than 30 minutes; the sick person seems confused or unusually sleepy; an infant or pregnant person is sick; urine output stops.

  4. One sick room, one cup, one towel. The sick person's items are not shared during illness. This is non-negotiable.

  5. Wash hands with soap and water. Not just sanitizer. Run water, use soap, scrub for 20 seconds, rinse. This applies after using the bathroom, before preparing food, and after any contact with the sick person or their environment.

Posting these rules in your household medical area, alongside your ORS recipe from dehydration assessment, means they are available when decision-making is hardest.

For this page to work, you need the supporting pages alongside it:

Sources and next steps

Last reviewed: 2026-05-22

Source hierarchy:

  1. IDSA 2017 Infectious Diarrhea Clinical Practice Guidelines (Shane et al., CID 65:e45-e80) (Tier 1, professional medical society guideline)
  2. IDSA/SHEA 2021 Focused Update — Clostridioides difficile Infection (Tier 1, professional medical society guideline)
  3. CDC Norovirus Clinical Guidance (Tier 1, federal public health agency)
  4. CDC E. coli / STEC Clinical Guidance (Tier 1, federal public health agency)
  5. CDC C. difficile Facts for Clinicians (Tier 1, federal public health agency)
  6. CDC Giardia Clinical Care (Tier 1, federal public health agency)
  7. CDC Cryptosporidium Clinical Care (Tier 1, federal public health agency)
  8. WHO Oral Rehydration Salts — Production of the new ORS (Tier 1, international health authority)

Legal/regional caveats: This page applies general IDSA and WHO guidance that is not jurisdiction-specific. Antibiotic prescribing in non-emergency settings requires a licensed provider in most countries. Ciprofloxacin resistance patterns vary significantly by region — local epidemiological patterns should inform empiric antibiotic choice when available. Pediatric drug dosing should be verified by a licensed provider whenever possible.

Safety stakes: life-safety topic — verify against current local/professional guidance before acting.

Next 3 links: