Cyclic Vomiting Syndrome – Causes, Symptoms, Diagnosis, Treatment and Ongoing care



An idiopathic chronic functional GI disorder characterized by discrete, recurrent, stereotypical episodes of high-intensity nausea and vomiting lasting hours to days, separated by symptom-free intervals

Cyclic vomiting syndrome (CVS) has a phasic pattern with four distinct phases.

  • Interepisodic: Symptom-free period
  • Prodromal: Often marked by nausea + abdominal pain; able to take oral medications
  • Vomiting: Nausea, vomiting, and retching
  • Recovery: Nausea remits and patient has recovered appetite, strength, and energy.





  • 0.04–1.9%
  • Whites more affected than other races
  • Predominant sex: Female > Male (55:45).

Risk Factors

  • Family history of migraine headaches
  • Depression
  • Anxiety
  • Chronic cannabis use


  • Possible matrilineal inheritance
  • A3243G mitochondrial DNA mutation
  • Ion-channel mutations

General Prevention

  • Handwashing to prevent upper respiratory infection (URI)
  • Adequate sleep
  • Avoiding triggers
  • Psychological testing and stress-reduction techniques


  • Unknown
  • Strong link between CVS and migraine, with similar symptoms, common coexistence in patients, and effectiveness of antimigraine therapy
  • Proposed mechanism:
    • Heightened neuronal excitability owing to enhanced ion permeability, mitochondrial deficits, or hormonal state → increased susceptibility to physical or psychological trigger → release of corticotropin-releasing-factor (CRF) → vomiting
    • Vomiting perpetuated by altered brain stem regulation → sustained vomiting


  • Unknown
  • Possible maternal inheritence
  • Multiple theories:
    • GI motility dysfunction
    • Autonomic dysfunction
    • Mitochondrial enzymopathies
    • Food allergy or intolerance

Commonly Associated Conditions

  • Irritable bowel syndrome (67%)
  • Headaches (52%)
  • Motion sickness (46%)
  • Migraines (11–40%)
  • Seizure disorder (5.6%)

Migraine, Cyclic vomiting syndrome, Headache, Nausea, Digestive Disorders, neuronal excitability, irritable bowel syndrome, stress reduction techniques, upper respiratory infection, depression anxiety, motion sickness,



  • Children with CVS often present with bilious emesis (83%), severe abdominal pain (80%) and/or hematemesis.
  • The North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition consensus statement recommends the following criteria to be fulfilled to diagnose CVS:
    • At least 5 attacks in any interval or a minimum of 3 attacks during a 6-month period
    • Episodic attacks of intense nausea and vomiting lasting 1 h to 10 days and occurring at least 1 week apart
    • Stereotypical pattern and symptoms in the individual patient
    • Vomiting during attacks occurs at least 4 times/h for at least 1 h
    • Return to baseline health between episodes
    • Not attributed to another disorder

Physical Exam

Dehydration evaluation (seen in 30%):

  • Orthostatic hypotension
  • Tachycardia
  • Skin turgor, decreased
  • Mucous membranes, dry

Diagnostic Tests & Interpretation


There are no specific laboratory findings to diagnose CVS. Initial tests are mainly for screening purposes and to exclude other diagnoses.

Initial lab tests

  • Electrolytes: Hypokalemia (Addison disease would show hyponatremia and hypoglycemia.)
  • Complete blood count (CBC): Hemoconcentration and leukocytosis
  • Amylase and lipase to check for pancreatitis
  • Erythrocyte sedimentation rate (ESR)
  • Hepatic transaminases: To exclude hepatitis or gallbladder disease
  • Urinalysis: Granular casts, ketosis
  • Urine pregnancy test
  • Lactate, ammonia, amino acids, urine organic acids during an acute episode for young children to exclude metabolic diseases

Follow-Up & Special Considerations


  • Anxiety and depression management
  • Cannabis cessation (if applicable)


Initial approach

  • Upper GI series to exclude malrotation
  • Small bowel follow-through
  • Abdominal ultrasound to exclude transient hydronephrosis, gallstones, and ureteropelvic junction obstruction

Follow-Up & Special Considerations

CT scan of head, abdomen, and pelvis to evaluate biliary and urinary tracts and exclude structural reason

Diagnostic Procedures/Surgery

  • Esophagogastroduodenoscopy (EGD): To evaluate for clinical suspicion of peptic ulcer disease or sign of hematemesis
  • Electroencephalogram (EEG): Seizure disorder evaluation
  • Gastric emptying studies
  • Autonomic testing
  • Neuropsychiatric testing

Differential Diagnosis

  • Evaluate for causes of vomiting:
    • GI: Surgical and nonsurgical
    • Urologic
    • Renal
    • Gynecologic
    • Neurologic
    • Endocrinologic
    • Ear/nose/throat (ENT)
    • Psychiatric, including Münchausen by proxy
    • Metabolic
  • Any child with suspected CVS should be evaluated for a possible metabolic or neurologic etiology of their symptoms if:
    • Child is <2 years of age.
    • Vomiting episodes are associated with other concurrent illnesses, prior fasting, or increased protein uptake.
    • Any focal findings on neurologic exam
    • Hypoglycemia, anion-gap metabolic acidosis, hyperammonia, or other findings suggestive of metabolic disorders



First Line

Lifestyle changes including avoidance of sleep deprivation, triggering foods, and motion sickness may reduce episode frequency. Prophylactic pharmacotherapy can be considered if the child is having repeated episodes requiring frequent hospitalization and school absences.

  • Prophylactic: Decreases frequency or severity by >50%:
    • Amitriptyline (67–73%): Children >5 years: 0.3–0.5 mg/kg/d; adults: 50–75 mg/kg/d (1,2,3)[C]
    • Propranolol (57%): Children: 0.5 mg/kg/d divided b.i.d.–t.i.d.; adults: 10–20 mg/d b.i.d.–t.i.d.) (4)[C]
    • Cyproheptadine (39–66%): Children <5 years: 0.3 mg/kg/d divided b.i.d.–t.i.d.; appetite stimulant (1)[C]
  • Abortive:
    • Ondansetron: Children: 0.3–0.4 mg/kg/dose q6h; adults: 4 mg IV/PO q6–8h (5)[C]
    • Lorazepam: Children: 0.05–0.1 mg/kg/dose IV (not to exceed 4 mg/dose); adults: 1–2 mg IM/IV q4–6h p.r.n.) (5)[C]
    • Sumatriptan: >40 kg/20 mg intranasal p.r.n. (5)[C]

Second Line

  • Prophylactic: Decreases frequency or severity by >50%:
    • Phenobarbital (79%): 2–3 mg/kg/d (4)[C]
    • Erythromycin (75%): 20 mg/kg/d divided b.i.d.–t.i.d. (4)[C]
  • Abortive:
    • Hydromorphone: Children: 0.015 mg/kg/dose IV for 1 dose; adults: 3 mg p.r.n. or 0.5–2 mg IM/SC × 1 dose (4,5)[C]
    • Diphenhydramine: Children: 1.25 mg/kg/dose q6h, not to exceed 300 mg/d; adults: 25–50 mg q4–6h p.r.n. (4,5)[C]

Additional Treatment

General Measures

  • Patient reassurance
  • Nonstimulating environment
  • Relaxation techniques
  • Avoid recreational drugs

Issues for Referral

Support's development and hosting

Mental health, weekly appointments

Additional Therapies

Relaxation techniques:

  • Deep breathing
  • Biofeedback
  • Guided imagery

Complementary and Alternative Medicine

Coenzyme Q may play a role in helping CVS (6)[A].

In-Patient Considerations

Initial Stabilization

  • IV fluids
  • IV ondansetron and lorazepam
  • Analgesia for pain

Admission Criteria

  • Dehydration requiring >2 L of IV fluids
  • Failure of outpatient management
  • Increased anion gap that reflects severe dehydration or metabolic decompensation

IV Fluids

Replacement of ongoing losses; may consider 10% dextrose-containing fluids to attenuate any metabolic crisis


  • Decrease stimulation; avoid noise and bright light.
  • Supportive care
  • Encourage relaxation techniques
  • Avoid unnecessary interruptions during sleep

Discharge Criteria

  • Resolution of vomiting phase
  • Pain managed with oral analgesia
  • Euvolemia
  • Appropriate oral intake

Ongoing Care

Follow-Up Recommendations

Patient Monitoring

  • Weekly appointments for severe cases
  • Monitoring of emesis-associated laboratory values: Hypokalemia, acid–base disturbances, ketosis
  • Regular outpatient visits for support


  • Foods rich in carbohydrates, proteins, vitamins, and minerals
  • Limit fats and spicy foods.
  • Avoid trigger foods: Chocolate, cheese, and monosodium glutamate (MSG).
  • Regular meal schedules
  • Maintenance of good hydration

Patient Education

  • Information and explanation about CVS may greatly alleviate the burden of illness among older patients.
  • Maintain vomiting diary to note patterns, which helps to identify potentially avoidable triggers in 75% of children.
  • Stress management techniques
  • Good sleep hygiene
  • Regular, moderate exercise
  • Online resources such as the Cyclic Vomiting Syndrome Association Web site at


  • Usually lasts 2.5–5.5 years
  • Vomiting resolves in 60% of children with CVS.
  • However, many children will continue to have somatic symptoms, including headache and abdominal pain.
  • 37% develop recurrent/migraine headaches.
  • 50–75% with prophylactic treatment are asymptomatic at 1 year.


Occur during vomiting phase:

  • Dehydration
  • Electrolyte derangement, including the syndrome of inappropriate antidiuretic hormone (SIADH)
  • Hematemesis
  • Peptic esophagitis
  • Mallory-Weiss tear
  • Weight loss
  • Hypovolemic shock


1. Andersen JM, Sugerman KS, Lockhart JR, et al. Effective prophylactic therapy for cyclic vomiting syndrome in children using amitriptyline or cyproheptadine. Pediatrics. 1997;100:977–81.

2. Prakash C, Clouse RE. Cyclic vomiting syndrome in adults: clinical features and response to tricyclic antidepressants. Am J Gastroenterol. 1999;94:2855–60.

3. Hejazi RA, Reddymasu SC, Namin F, Lavenbarg T, Foran P, McCallum RW et al. Efficacy of tricyclic antidepressant therapy in adults with cyclic vomiting syndrome: a two-year follow-up study. J Clin Gastroenterol. 2010;44:18–21.

4. Pareek N, et al. Cyclic vomiting syndrome: What a gastroenterologist needs to know. Am J Gastroenterology.2007;102(12):2832–40.

5. Li BU. Cyclic Vomiting Syndrome. Curr Treat Options Gastroenterol. 2000;3:395–402.

6. Boles RG, Lovett-Barr MR, Preston A, Li BU, Adams K et al. Treatment of cyclic vomiting syndrome with co-enzyme Q10 and amitriptyline, a retrospective study. BMC Neurol. 2010;10:10.

Additional Reading

Cyclic Vomiting Syndrome Association: Website:

Fitzpatrick E, Bourke B, Drumm B, Rowland M et al. Outcome for children with cyclical vomiting syndrome. Arch. Dis. Child.2007;92:1001–4.

Fleisher DR. Empiric guidelines for the management of cyclic vomiting syndrome. Available at:

Li BU, Balint JP. Cyclic vomiting syndrome: evolution in our understanding of a brain-gut disorder. Adv Pediatr. 2000;47:117–60.

Li BU, Lefevre F, Chelimsky GG, et al. North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition consensus statement on the diagnosis and management of cyclic vomiting syndrome. J Pediatr Gastroenterol Nutr. 2008;47:379–93.

National digestive diseases information clearinghouse:



536.2 Persistent vomiting


18773000 Cyclical vomiting syndrome (disorder)

Clinical Pearls

  • Identify patterns and triggers for cycles.
  • Encourage sleep hygiene, stress management, and appropriate diet.
  • Treatment in the vomiting phase requires pharmacologic and psychosocial interventions.
  • Educating families about CVS can help to reduce the burden of illness among patients.

About the author

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