What is Periodic Vomiting Syndrome?

Cyclic vomiting syndrome (CVS) is a condition that causes recurring episodes of nausea and vomiting over hours or days. CVS is more common in children and is estimated to affect about 2% of school-age children. It usually begins between the ages of 3 and 7 and is more common in girls than boys.

This article explains the symptoms, causes, and triggers of cyclic vomiting syndrome. It also discusses how to diagnose and treat CVS.

Periodic vomiting syndrome symptoms

Children with CVS often experience episodes or cycles of nausea, vomiting, and gagging that last from hours to weeks. Children may gag when they brush their teeth, look at food, think about it, or smell it.

Children may also be less active and have a decreased appetite during episodes. They may want to stay home rather than with other children to avoid the embarrassment of throwing up in front of them.

Unless the child also has viral gastroenteritis (“stomach flu”), symptoms of CVS do not include fever, diarrhea, pain, or respiratory symptoms.

Symptoms that accompany nausea and vomiting in CVS include:

  • abdominal discomfort
  • headache
  • pale complexion
  • Dehydration causes sunken eyes

Once an episode is over, children usually have no symptoms until the next episode.

Most children with CVS will grow up in adolescence. In some cases, however, it can persist throughout adolescence and adulthood. It can start at any age, even though it usually begins in childhood. Many people who had CVS as children went on to develop migraines as adults.

When to seek help

In general, CVS is not dangerous. However, if your child has any of the following signs, you need immediate medical attention:

  • severe dizziness
  • Inability to walk without assistance
  • syncope
  • vomiting blood
  • Difficulty staying awake or being awake
  • seizures or convulsions

Stages of Periodic Vomiting Syndrome

The onset of periodic vomiting syndrome goes through four distinct phases. Cycles can last for hours, days or weeks. Usually, symptoms go away for a while before reappearing.

The stages of CVS include:

  • Prodrome: Your child may feel nauseous, dizzy, or slightly nauseated.
  • Vomiting: Your child will experience nausea, vomiting, retching, and may not be able to control food and drink.
  • Recovery: Your child may start to feel better and have an increased appetite, but may still not feel completely better.
  • Well Stage: Symptoms of CVS have ceased. Your child should avoid certain foods or other triggers until they feel fully recovered.

After a few episodes of a CVS episode, children or their parents may be able to sense the timing of the episode. This can help them identify what might trigger it so they can avoid those triggers in the future.


CVS is thought to cause problems with gastrointestinal (GI) function due to abnormal connections between neurons in the brain and the gastrointestinal system (or “gut”). It is not caused by viruses or other diseases of the gastrointestinal system.

Most children with this disorder have a family history of migraines. Many experts believe the two are related. In fact, cyclic vomiting syndrome is sometimes called an abdominal migraine.

One study found that more than half of children went on to experience migraines after experiencing periodic vomiting symptoms.

How to deal with your child’s migraines


Usually, CVS kicks in due to some trigger. In general, children with CVS are sensitive to specific triggers and not others. Here are some common CVS triggers:

  • Stress – Sometimes children and their parents may not realize that the child is under stress and CVS is the only symptom
  • tiredness, sleepiness, or jet lag
  • certain smells, especially the smells of foods your child doesn’t like
  • Motion sickness – This can be caused by riding in a car, plane, boat or roller coaster.
  • Stomach flu – Although CVS is not viral gastroenteritis, sometimes children experience periodic vomiting during or after stomach flu
  • become overheated or overexcited


Periodic vomiting syndrome is classified as a functional gastrointestinal disorder. This means that there is nothing wrong with the physical structure of the GI system. Instead, a diagnosis is made by looking at typical symptom patterns. No specific test can confirm the diagnosis.

Doctors also want to rule out other conditions that may cause the same symptoms as CVS. (This is called differential diagnosis.)

Conditions that can cause similar symptoms include:

  • viral gastroenteritis
  • Gastroesophageal Reflux Disease (GERD)
  • certain metabolic disorders
  • brain tumor
  • Addison is sick
  • Intestinal malrotation and volvulusA condition in which the bowel moves and becomes tangled

Tests that can be performed include:

  • Brain imaging tests, such as computed tomography (CT) scans or magnetic resonance imaging (MRI)
  • metabolic testing
  • Abdominal ultrasound
  • Upper Gastrointestinal X-ray Series with Small Bowel Tracking (UGI-SBFT), in which images of the esophagus, stomach, and small intestine are taken

Sometimes, healthcare providers recommend treating symptoms as being caused by CVS. If the child responds to treatment, this confirms the CVS diagnosis.


The acute phase of CVS is the phase in which symptoms are active. The goal of acute treatment is to prevent problems such as dehydration. Chronic treatment focuses on preventing more episodes from recurring in the long term.

acute treatment

During an acute vomiting episode, treatment is designed to make your child as comfortable as possible.

Treatment may include:

  • Rest in a quiet, dark room
  • Medicines to prevent nausea and vomiting, such as Zofran (ondansetron), Imitrex (sumatriptan), Catapres (clonidine), or benzodiazepines
  • sugary drinks

If your child is severely dehydrated, they may need intravenous fluids (IV) in the hospital.

chronic treatment

The best treatment for recurrent vomiting is prevention. Medications used to treat migraines in children can also be used to prevent recurrent vomiting. These include:

  • Periactin (cyproheptadine)
  • Inderal (Propanol)
  • Elavil (amitriptyline)

avoid triggering

If your child has been diagnosed with CVS, you may want to try to identify the triggers for these events.

Some migraine sufferers keep a headache diary to document what triggered a particular migraine attack. Likewise, keeping CVS logs can help you identify triggers for CVS events. This can help you avoid them if possible.


Researchers investigated the possibility of using the B vitamin riboflavin to prevent recurrent vomiting. Riboflavin is known to sometimes help prevent migraines. Riboflavin is found in whole grains as well as in almonds, spinach, and mushrooms. It also comes in supplement form.

A small European study in 2016 found that treating children diagnosed with CVS with riboflavin for 12 months helped improve the condition. While this study was too small to include riboflavin as standard of care, you may want to ask your pediatrician if adding this vitamin to your child’s treatment plan would help.

Children with periodic vomiting appear to be at increased risk for anxiety and depression. In this case, it may be useful to treat these with therapy and/or medication.


Periodic vomiting syndrome is a disorder that causes episodes of vomiting and nausea. It can happen within hours, days or sometimes weeks. CVS is more common in children than in adults. CVS is diagnosed primarily by excluding other diseases with similar symptoms. Often, children with CVS develop migraines as adults.

VigorTip words

Although periodic vomiting syndrome can be unpleasant and devastating, most children with CVS have symptoms that outweigh their symptoms. Knowing how to control vomiting in children can prevent them from becoming overly dehydrated. If your child has repeated episodes of CVS, talk to their pediatrician. Preventive medications, such as those used for migraines, are also very effective for CVS.

Frequently Asked Questions

  • What causes chronic vomiting?

    Chronic vomiting can be caused by a malfunction in the relationship between the nervous system and the gastrointestinal system. In CVS, periodic vomiting is thought to be caused by hormones and the brain. In most cases, there are no dangerous underlying medical problems associated with it.

  • How do you stop vomiting continuously?

    You can stop vomiting by avoiding triggers that trigger it, such as stress or certain smells. Your healthcare provider may also prescribe medications to prevent nausea and vomiting.