??🤮 Cyclic Vomiting Syndrome (CVS) in Children: Episodes of Vomiting That Come and Go

✅ Cyclic vomiting syndrome causes repeated, stereotyped episodes of intense vomiting separated by normal, well periods.
It is often linked to the migraine pathway—and the right plan can reduce episodes and ER visits.

1) 🧾 Quick “At-a-glance” box (top of page)

✅ Condition name: Cyclic Vomiting Syndrome (CVS)
Common names: Cyclic vomiting, recurrent vomiting attacks, “vomiting spells”

Plain-language summary (2–3 lines):
CVS is a condition where a child has sudden episodes of severe nausea and vomiting that look similar each time, then fully (or almost fully) recovers between episodes. Episodes can be triggered by illness, stress, lack of sleep, or certain foods. Many children with CVS have a personal or family history of migraine.

Who it affects (typical ages):
Often starts in preschool or school-age, but can occur at any age (including teens).

✅ What parents should do today:

• If your child is currently in an episode: focus on hydration and early anti-nausea plan (if prescribed).
• Track patterns and triggers.
• Create a clear “episode action plan” for home, school, and ER.

⚠️ Red flags that need urgent/ER care:

• Dehydration (no urine 8–12 hours, very sleepy, dizzy)
• Vomiting green (bilious) or vomiting blood / black “coffee-ground”
• Severe belly pain with hard/swollen belly
• Severe headache with confusion/neck stiffness
• New neurologic symptoms (weakness, trouble walking, severe behavior change)
• First-ever severe episode in a young child (needs evaluation)

🟡 When to see the family doctor/clinic:

• Recurrent vomiting episodes with well intervals
• Missed school, weight loss, or frequent ER visits
• Need for a prevention plan and trigger management
• Consider referral to pediatric gastroenterology and/or neurology

2) 🧠 What it is (plain language)

CVS is:

• episodes of vomiting that come on suddenly,
• often last hours to days,
• then the child returns to normal between episodes.

A hallmark is that episodes are often predictable in pattern:

• same time of day (often early morning),
• same associated symptoms,
• similar duration.

The 4 phases (easy parent language)

1. Well phase: child feels normal
2. Warning phase (prodrome): nausea, tired, pale, mood change
3. Vomiting phase: repeated vomiting, can’t keep fluids down
4. Recovery phase: vomiting stops, slowly returns to eating/drinking

What part of the body is involved? (small diagram required)

Common myths vs facts

• Myth: “CVS is just a stomach bug over and over.”
  Fact: CVS episodes are not infections; kids are well in between.
• Myth: “It’s anxiety only.”
  Fact: Stress can trigger episodes, but CVS is a brain–gut disorder often linked to migraine biology.
• Myth: “Nothing helps.”
  Fact: A plan with early treatment and prevention often helps significantly.

3) 🧩 Why it happens (causes & triggers)

CVS is often connected to the migraine system, involving:

• brain signaling,
• stress hormones,
• gut nervous system,
• and nausea/vomiting centers.

Common triggers

• Viral illness
• Stress/excitement (holidays, events)
• Lack of sleep
• Skipping meals/fasting
• Dehydration
• Certain foods (some children: chocolate, caffeine, cheese)
• Motion sickness
• Menstruation in teens

Less common but important causes to consider (brief)

When vomiting is recurrent, clinicians must ensure it is not:

• GI obstruction or malrotation (especially if bilious vomiting)
• Metabolic disorders (especially in young children or with fasting intolerance)
• Increased intracranial pressure (persistent morning headache, neuro signs)
• Kidney issues (hydronephrosis), adrenal issues (rare)
• Cannabinoid hyperemesis in teens using cannabis (important differential)

Risk factors

• Personal or family history of migraine
• Motion sickness
• Anxiety sensitivity
• Sleep problems

4) 👀 What parents might notice (symptoms)

Typical symptoms during episodes

• Repeated vomiting (can be many times/hour)
• Severe nausea
• Pallor, sweating
• Belly pain
• Headache or light sensitivity (migraine features)
• Lethargy
• Ketone breath or “starvation” signs from not eating

Symptoms between episodes

• Often completely normal
• Sometimes mild nausea or abdominal discomfort

Symptoms by age group

• Preschool: vomiting + lethargy, hard to describe nausea
• School-age: nausea warning phase more clear; headache may appear
• Teens: migraine symptoms, menstruation triggers, consider cannabis use as differential if relevant

What’s normal vs what’s not normal

✅ Typical CVS:

• stereotyped episodes
• normal between episodes
• similar triggers

⚠️ Not typical / urgent evaluation:

• green (bilious) vomiting
• persistent daily vomiting without well periods
• focal neurologic signs
• severe progressive headaches
• weight loss without recovery periods

Symptom tracker (what to write down)

• start time, duration, end time
• number of vomits
• ability to keep fluids down
• urine output
• triggers (sleep loss, stress, fasting)
• associated symptoms (headache, light sensitivity)
• meds tried and response

5) 🏠 Home care and what helps (step-by-step)

✅ CVS is all about early action. Treating in the warning phase can sometimes shorten or stop the episode.

✅ What to do in the first 24–48 hours (episode plan)

Step 1: Move to “quiet mode”

• dark, quiet room
• minimal stimulation
• child rests (many kids feel better sleeping)

Step 2: Hydration strategy

✅ Do this now:

• Start tiny sips of oral rehydration solution if tolerated.
• 5–10 mL every 2–3 minutes (young kids), small sips frequently (older kids).
• If vomiting continues, pause 5–10 minutes then restart with smaller sips.

Step 3: Use prescribed “rescue meds” early (if you have them)

Common clinician-prescribed options may include:

• anti-nausea medicine (example: ondansetron)
• migraine-style rescue medication in select children
• acid protection during episodes if needed

(Use only as prescribed.)

Step 4: Avoid triggers during recovery

• avoid fasting; small frequent intake as soon as tolerated
• prioritize sleep and hydration for several days after

What usually makes it worse

• bright light/noise stimulation
• forcing food early
• long gaps without fluids
• delaying the rescue plan until dehydration starts

6) ⛔ What NOT to do (common mistakes)

• Don’t wait “until morning” if your child is not urinating and can’t keep fluids down.
• Don’t force large drinks (triggers vomiting).
• Don’t use multiple OTC meds without guidance.
• Don’t ignore bilious (green) vomiting—this is not typical CVS and needs urgent evaluation.

OTC medication cautions

• Avoid NSAIDs if dehydrated and vomiting heavily.
• Avoid repeated sedating medicines.

7) 🚦 When to worry: triage guidance

🔴 Call 911 / Emergency now

• Child is very hard to wake, fainting, breathing trouble, seizure
• Severe dehydration with collapse

Example: “My child is not responding normally and looks very weak.”

🟠 Same-day urgent visit

• No urine 8–12 hours, very dry mouth, sunken eyes
• Persistent vomiting cannot keep any fluids down
• Green vomiting or vomiting blood/black material
• Severe belly pain with hard/swollen abdomen
• New neurologic symptoms or severe headache with confusion/neck stiffness

Example: “Vomiting all day and hasn’t peed since morning.”

🟡 Book a routine appointment

• Recurrent stereotyped episodes with well intervals
• Missed school, weight loss, frequent ER visits
• Need a prevention plan and rescue medication plan
• Possible migraine features or family history of migraine

Example: “Every 4–6 weeks my child has the same vomiting attack.”

🟢 Watch at home

• Mild episode with stable hydration (urinating), improving with early home plan and clinician guidance

8) 🩺 How doctors diagnose it (what to expect)

What the clinician will ask

• Episode pattern and stereotypy
• Frequency and duration
• Triggers (sleep, stress, fasting)
• Family history of migraine
• Symptoms between episodes
• Red flags: bilious vomiting, neurologic symptoms, poor growth

Physical exam basics

• Hydration status
• Abdominal exam
• Neuro exam
• Growth trend

Possible tests (and why)

Usually done to rule out other causes, especially early on:

• Blood tests during episodes (electrolytes, glucose, ketones)
• Urine analysis
• Imaging if concern for obstruction (especially bilious vomiting)
• Consider metabolic testing if early onset or fasting intolerance
• Sometimes brain imaging if neurologic red flags

What tests are usually not needed

• Repeated extensive testing once CVS diagnosis is clear and red flags are absent

What results might mean

• Normal “rule-out” evaluation + classic pattern supports CVS
• Abnormal findings point to alternative diagnosis that needs specific treatment

9) 🧰 Treatment options

First-line treatment

• Rescue plan for episodes (hydration + early anti-nausea)
• Trigger management:
  • regular sleep
  • regular meals (avoid fasting)
  • hydration
  • stress support
• School plan (nurse aware; early rescue)

If not improving (next steps)

• Preventive medication may be considered by clinician if:
  • frequent episodes
  • severe dehydration/ER visits
  • significant school disruption
• Migraine-style prevention strategies (clinician-directed)
• Referral to pediatric gastroenterology and/or neurology

Severe cases (hospital care)

• IV fluids and anti-nausea medication
• Electrolyte correction
• Evaluation for alternative diagnosis if pattern changes

Medication/treatment details (parent-friendly)

Oral rehydration

• What it does: prevents dehydration and reduces ER need
• How to give: tiny sips often
• Common side effects: none

Ondansetron (clinician-directed)

• What it does: reduces vomiting so hydration can work
• How to give: at the first sign of episode (as prescribed)
• Common side effects: constipation, headache
• Serious side effects (rare): rhythm issues in select risk contexts
• When to stop/seek help: fainting, allergic reaction, worsening confusion
• Interactions: clinician reviews QT-related risk meds

Preventive therapy

• Purpose: reduce episode frequency/severity
• Requires clinician plan and follow-up

10) ⏳ Expected course & prognosis

• Some children have episodes for years; many improve over time.
• Some transition into more classic migraine headaches as they get older.
• With a strong plan, many families see fewer ER visits and faster recovery.

What “getting better” looks like

• longer intervals between episodes
• less vomiting and quicker recovery
• better hydration during episodes

What “getting worse” looks like

• more frequent episodes
• changing pattern (new red flags)
• weight loss or poor growth

Return to school/daycare/sports

• Most kids can return once:
  • vomiting has stopped
  • hydration is stable
  • energy returns
• School nurse action plan is very helpful.

11) ⚠️ Complications (brief but clear)

Common complications

• Dehydration
• ER visits and missed school
• Anxiety around episodes
• Dental enamel wear with frequent vomiting

Rare serious complications

• Electrolyte imbalance requiring IV therapy
• Aspiration (rare)

12) 🛡️ Prevention and reducing future episodes

• Protect sleep (consistent bed and wake times)
• Avoid fasting (breakfast matters)
• Hydration routine
• Early rescue plan at first warning sign
• Identify and reduce personal triggers
• Manage stress with coping tools (breathing, CBT strategies)

13) 🌟 Special situations

Infants

Recurrent vomiting in infants needs careful evaluation—CVS is less common early.

Teens

• Consider migraine triggers, menstruation patterns
• Consider cannabis use as a differential if recurrent vomiting and relief with hot showers is reported

Kids with chronic conditions

• Lower threshold for hospital hydration and evaluation
• Coordinate rescue plan with care team

Neurodevelopmental differences/autism

• Use visual action plan, preferred cups, low-stimulation environment
• School plan is especially helpful

Travel considerations

• Carry oral rehydration packets and rescue meds
• Avoid missed meals and sleep loss

School/daycare notes

• Provide an episode plan:
  • early anti-nausea (if prescribed)
  • hydration sips
  • calm dark room
  • parent contact

14) 📅 Follow-up plan

• Follow up after diagnosis to create:
  • home rescue plan
  • school plan
  • prevention plan if needed
• Follow up sooner if:
  • pattern changes
  • bilious vomiting occurs
  • neurologic symptoms occur
  • weight loss develops
• Bring:
  • episode diary and triggers
  • medication response notes
  • ER visit summaries if any

15) ❓ Parent FAQs

“Is it contagious?”

No. CVS is not an infection.

“Can my child eat ___?”

Between episodes: yes, balanced diet. During episodes: focus on hydration; small bland foods only after vomiting settles.

“Can they bathe/swim/exercise?”

Yes between episodes. During episodes, rest is best.

“Will they outgrow it?”

Many children improve over time. Some may develop migraine headaches later.

“When can we stop treatment?”

When episodes have been absent or rare for a long time and your clinician agrees. Many families still keep an emergency plan available “just in case.”

16) 🧾 Printable tools (high-value add-ons)

🧾 Printable: One-Page Action Plan (Cyclic Vomiting Syndrome)

Warning phase (first signs):

• Quiet dark room
• Start tiny sips ORS (if tolerated)
• Give rescue medication as prescribed
• Avoid stimulation

Vomiting phase:

• 5–10 mL every 2–3 minutes (young) / frequent small sips (older)
• If vomiting → pause 5–10 minutes → restart smaller
• Track urine output

Go to urgent care if:

• no urine 8–12 hours
• cannot keep fluids down
• green vomit or blood/black vomit
• severe belly pain/hard belly
• confusion, severe headache, or new neurologic symptoms

🧾 Printable: Medication Schedule Box

(Use only if prescribed.)

• Rescue medication: __________________ Time: ______
• Second dose if advised: _____________ Time: ______
• Notes / side effects: ____________________________

🧾 Printable: Episode Diary / Tracker

Episode # ____

• Start date/time: ______ End date/time: ______
• Vomits/hour (peak): ______
• Fluids tolerated: ______________________________
• Urine output (times/day): ______________________
• Triggers before episode (sleep loss/stress/illness/fasting): ______
• Rescue meds used + response: ____________________

🧾 Printable: “Red Flags” Fridge Sheet

⚠️ Urgent: dehydration (no urine 8–12 hours), green vomiting, blood/black vomit, severe belly pain/hard belly, confusion, severe headache/neck stiffness, new weakness/trouble walking.

🧾 Printable: School/Daycare Instructions Page (CVS)

• Child may have predictable vomiting episodes
• Provide quiet low-stimulation space
• Offer tiny sips of ORS if tolerated
• Give prescribed rescue medication only per parent instructions
• Call parent early (before dehydration)
• Call emergency services if breathing trouble, severe lethargy, or red flags

17) 📚 Credible sources + last updated date

Trusted references (examples):

• Children’s hospital resources on cyclic vomiting syndrome
• Pediatric GI society information on CVS and functional vomiting disorders
• Migraine education resources for children and teens

Last reviewed/updated on: 2025-12-30
Local guidance may differ based on your region and your child’s health history.

🧡 Safety disclaimer

This guide supports—not replaces—medical care. If you are worried about your child, trust your instincts and seek urgent medical assessment.

This guide was fully developed & reviewed by Dr. Mohammad Hussein, MD, FRCPC ROYAL COLLEGE–CERTIFIED PEDIATRICIAN & PEDIATRIC GASTROENTEROLOGIST Board-certified pediatrician and pediatric gastroenterologist (Royal College of Physicians and Surgeons of Canada) with expertise in inflammatory bowel disease, eosinophilic gastrointestinal disorders, motility and functional testing, and complex nutrition across diverse international practice settings.

To book an online assessment Email Dr. Hussein’s Assistant Elizabeth Gray at: Elizabeth.Gray@pedsgimind.ca
In the email subject, please write: New Assessment Appointment with Dr. Hussein

Important: This appointment is completely online as Dr. Hussein is currently working overseas. This service is not covered by OHIP