Cyclic vomiting syndrome (CVS)

Cyclic vomiting syndrome: Description

Cyclic vomiting syndrome (CVS) is an uncommon chronic functional disorder that is characterized by the severe episodic vomiting (paroxysmal) of unknown etiology.
CVS affects both children and adults and involves paroxysms of recurrent vomiting and nausea. An episode may last a few hours or even up to several days and usually is followed by a symptom-free period.


The exact cause of CVS is unknown. Several possible reasons of the condition were proposed such as:
– increased motility of the gastrointestinal tract;

– dysfunction of the central nervous system (so-called brain-gut mechanism) or autonomic nervous system (sympathetic hyperresponsiveness);

– hormone imbalance;

– inherited disorders (mitochondrial DNA mutations are involved among children).
It has been reported that in families with the history of migraine episodes of CVS are more likely to occur. Sometimes the episodes are following the intensive headache or are followed by the migraine. Almost 80% of children and 25% of adults who suffer from CVS also complain of migraines.
This has caused the belief that CVS is a multifactorial disease – a diseased caused by several different factors:  genetic, autonomic, central, and environmental.

cyclic vomiting syndrome
Risk factors

The episodes of CVS are usually triggered by the emotional stress, migraines, infections, food intake (especially cheese or chocolate), weather change, physical exhaustion and irregular eating (overeating or fasting etc).
The chronic intake of marijuana is also known to cause CVS.

[See also: MERS (Middle East Respiratory Syndrome)]

Symptoms of cyclic vomiting syndrome

The onset of the disease typically takes place when a child is 3-7 years old. It is estimated that CVS lasts an average of 2.5-5.5 years and resolves in late childhood or early adolescence. Only a few patients present symptoms of the disorder through adulthood.
Severe sudden vomiting and nausea can last hours to several days. Other symptoms may include heaving or gagging, dizziness, fever, abdominal pain, diarrhea, headache and sensitivity to light.

The intensity of the symptoms vary during the cycle:
– Prodrome phase – the person feels dizzy, sometimes increased sweating and abdominal pain. The person is pale.
– Vomiting phase – occurs nausea, vomiting and retching. In severe cases the affected person may be unresponsive and immobile. This phase lasts from hours to days.

– Recovery phase – gradually the person’s health improves.
– Well phase – typically between the periods of vomiting the person feels well.
Cyclic vomiting syndrome can cause some complications: loss of water and electrolytes (dehydration), injury to the esophagus by the stomach acid and teeth enamel corrosion.



To identify the diagnosis a precise medical and family history should be taken, a physical examination, blood, urine and imagine testing, gastrointestinal endoscopy are done.



The treatment of cyclic vomiting syndrome is symptomatic.
In prodrome phase the treatment is used in order to prevent the episode of vomiting from occurring. Children and adults may use  ondansetron (Zofran) or lorazepam (Ativan) for nausea, ibuprofen for abdominal pain, ranitidine (Zantac), lansoprazole (Prevacid), or omeprazole (Prilosec, Zegerid) to control stomach acid production, sumatriptan (Imitrex) for migraines.
During a vomiting phase medications for pain, nausea, and reducing stomach acid and anxiety, anti-migraine medications (sumatriptan) to stop symptoms of a migraine or possibly stop an episode in progress are used. The hospitalization is recommended in case of severe nausea and vomiting. When dehydration occurs, intravenous injection fluids and medications are needed. If an episode continues for several days, a patient needs intravenous injections of nutrition.
During the recovery phase a replacement of lost water and electrolytes is necessary.
During the well phase  amitriptyline (Elavil), propranolol (Inderal), cyproheptadine (Periactin) are used to reduce the frequency of the cycles of vomiting, prevent them and lessen their severity.