History
Cycling vomiting syndrome (CVS) is characterized by recurrent, discrete, stereotypical episodes of rapid-fire vomiting between varying periods of completely normal health (see the image below). This on-and-off stereotypical pattern of vomiting is nearly pathognomonic of CVS.

Although periods of complete normality typically occur between episodes, many adult patients lose the cyclic pattern of symptoms over time, and 63% of them develop inter episodic symptoms (often nausea) between episodes; this pattern is termed coalescence. [8]
The Rome IV diagnostic criteria for CVS in children include of the following, both of which must be met [35] :
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At least 2 periods of unremitting vomiting with or without retching, lasting hours to days within a 6-month period
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A return to the usual state of health that lasts weeks to months
Because this 2-episode cutoff resulted in a significant number of misdiagnoses, the guidelines were modified by the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition (NASPGHAN) as follows (all criteria must be met) [36] :
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At least 5 episodes, or a minimum of 3 over a 6-month period
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Episodic attacks of intense nausea and vomiting lasting 1 hour to 10 days, occurring at least 1 week apart
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Stereotypical pattern and symptoms in the individual patient
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Vomiting during episodes occurs at least 4 times an hour for at least 1 hour
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A return to baseline health during episodes
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Symptoms cannot be attributed to another disorder
The Rome IV criteria left the minimum number of 2 episodes to diagnose CVS unchanged to promote early diagnosis. The Rome IV criteria also removed the word “nausea” from the guideline as it was difficult to assess. [35]
The Rome III criteria for CVS in adults include the following:
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Stereotypical episodes of vomiting regarding onset (acute) and duration (< 1 week)
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A minimum of 3 discrete episodes in the preceding year
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Absence of nausea and vomiting between episodes
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No metabolic, gastrointestinal (GI), or central nervous system (CNS) structural or biochemical disorders
Supportive criteria include a history of migraine headaches and a family history of migraine headaches.
The vomiting in CVS is typically much more severe and intermittent than that observed in gastroesophageal reflux. When children with CVS were compared with children with chronic vomiting, they had a much higher peak rate of emeses per hour (12.6 vs 1.9) but far fewer episodes per month (1.5 vs 36). [1] A cutoff criterion of at least 4 emeses per hour at peak and fewer than 2 episodes per week was 92% sensitive and 100% specific for the final diagnosis of CVS. [37]
With a larger cohort, the median peak rate of emeses was still 6 times per hour. [16] Only Bacillus cereus food poisoning matches this high intensity of emesis. [30] This singularly severe vomiting (so-called cyclic vomiting pattern) typifies patients with CVS and helps point toward a disorder that is localized outside the GI tract.
The stereotypical “on-off” pattern often begins with a prodrome of nausea and pallor. Vomiting peaks in the first hour and then begins to decline over the ensuing 4-8 hours, lasting a mean of 24 hours (median, 43 hours). Episodes commonly occur in the early morning (2:00-4:00 AM) or upon awakening (6:00-8:00 AM). The recovery period from the end of vomiting to the point of being able to eat and play lasts a mere 5 hours. Despite the implication of the term “cyclic,” only one half of patients have a stable periodicity; the rest have sporadic episodes. [30]
Besides vomiting, patients may also experience other GI symptoms. Abdominal pain is present in 80% of patients and may initially be severe enough to mimic acute abdomen and result in a laparotomy. [16] Patients may also have epigastric pain secondary to peptic injury of the esophagus.
Most patients experience retching (79%) and nausea (82%). They typically describe the nausea as the most distressing symptom [1] : It is unrelenting, is completely unrelieved by vomiting, and disappears only when the child is asleep or the episode is over. Many of the behavioral symptoms commonly observed in patients with CVS (eg, fetal positioning, social withdrawal, and turning off lights and televisions) are attempts to lessen this severe nausea. [30]
Fever, diarrhea, or both are noted in approximately one third of CVS patients, complicating the differentiation of this condition from gastroenteritis. These findings are likely due to associated autonomic symptoms, which are also common, particularly lethargy (93%) and pallor (91%). [1] Lethargy may be profound, and patients may be unable to walk or talk or may appear comatose. Excessive salivation (27%) can also be dramatic. [1]
Many patients with CVS have neurologic symptoms, which support the relation between migraines and CVS. Symptoms include headache (42%), photophobia (38%), phonophobia (30%), and vertigo (26%). Because less than half the patients with CVS have classic migraine symptoms, these symptoms cannot be used as diagnostic criteria for a migraine variant. [1]
Approximately 68% of families are able to identify events that appear to precipitate a patient’s episode. [6, 16, 19, 38] The most common precipitating event is infection (41%), particularly chronic sinusitis. [30] Psychological stresses (34%) and food products, including chocolate, cheese, and monosodium glutamate (MSG), rank close behind chronic sinusitis. Positive excitement, such as birthdays, holidays, vacations, and school outings, appear to trigger more episodes than do negative stresses.
Others recognize physical exhaustion or lack of sleep (18%), atopic events (13%), motion sickness (9%), and menses (13%) as triggers. [30] Many patients experience remission in the summer, when the number of infections and school stressors decline. [39]
The terms “cyclic vomiting syndrome” and “abdominal migraine” have often been used interchangeably because of the considerable overlap in clinical criteria. Indeed, except for vomiting, the key criteria for abdominal migraines are identical to those for CVS and include the following:
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Recurrent, stereotypical, and severe episodes of abdominal pain
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Punctuating well periods
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Autonomic symptoms (eg, pallor, lethargy)
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Family history of migraine headaches
Because 80% of children with CVS have abdominal pain, and 50% of those with abdominal pain vomit, many children can be diagnosed with either CVS or abdominal migraine. When both symptoms are present, the authors use the predominant or more consistent symptom as the primary label.
The following 3 additional criteria help strengthen the diagnosis of CVS [30] :
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Negative screening test results to exclude common GI, hepatobiliary, renal, metabolic, and endocrine disorders
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Subsequent development of migraine headaches
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A positive response to antimigraine medications
Clinical features of CVS are summarized in Table 2 below. [40]
Table 2. Clinical Features in Adults and Children with Cyclic Vomiting Syndrome (Open Table in a new window)
Feature |
Children |
Adults |
Age of onset |
4.8 years (earliest, 6 days) |
35 years (latest, 73 years) |
Delay in diagnosis |
2.6 years |
8 years |
Female-to-male ratio |
57:43 |
17:24 |
Frequency |
Every 2-4 weeks |
Every 3 months |
Duration (mean) |
1-2 days (range, 1-10 days) |
6 days (range, 1-21 days) |
Periodicity |
49% |
Not reported |
Early morning onset |
42% |
50% |
Stereotypical episodes |
99% |
85% |
Prodrome |
72%, 1.5 hours |
93% |
Symptoms |
Nausea, anorexia, pallor |
Nausea, epigastric pain |
Recovery to oral feeding |
6 hours |
24 hours |
Relieving factors |
Deep sleep |
Hot bath or shower (56%) |
Precipitating factors |
Stress (47%), infection (31%) |
Menses (57%), anxiety |
Comorbid conditions |
Anxiety |
Not reported |
Inter episodic nausea |
< 6% |
63% |
Coalescence of episodes |
Few |
50% |
Vomiting |
6 episodes/hr at peak, bile (81%) |
8.5 episodes/hr |
Systemic symptoms |
Pallor, salivation, listlessness |
Intense thirst (33%) |
GI symptoms |
Anorexia, nausea, diarrhea, abdominal pain |
Abdominal pain, diarrhea |
Neurologic symptoms |
Headache, photophobia, phonophobia, abdominal pain |
Irritability, confusion |
Natural history |
=28% progress to migraine |
Not reported |
Family history |
82% |
57% |
Complications |
Dehydration, esophagitis |
Dehydration, esophagitis, laparotomy (18%) |
Morbidity |
14-25 days of missed school per year |
32% completely disabled |
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Cyclic versus chronic temporal patterns of recurrent vomiting. Number of emeses is plotted over 2-month period. Chronic pattern, represented by thin dashed line, has low grade on nearly daily basis (eg, gastroesophageal reflux). Cyclic pattern, represented by heavy solid line, involves high-intensity episodes intermittently once every several weeks (eg, cyclic vomiting syndrome).