Cyclic vomiting syndrome, or CVS, is a functional gastrointestinal (GI) disorder that causes sudden, repeated attacks—called episodes—of severe nausea and vomiting. Episodes can last from a few hours to several days. The episodes are separated by periods without nausea or vomiting. The time between episodes can be a few weeks to several months. Episodes can happen regularly or at random. Episodes can be so severe that you may have to stay in bed for days, unable to go to school or work. You may need treatment at an emergency room or a hospital during episodes. Cyclic vomiting syndrome can affect you for years or decades.

CVS is not chronic vomiting that lasts weeks without stopping. CVS is not a condition that has a definite cause, such as chemotherapy.

Cyclic vomiting syndrome is a disorder that causes recurrent episodes of nausea, vomiting, and tiredness (lethargy). This condition is diagnosed most often in young children, but it can affect people of any age.

The episodes of nausea, vomiting, and lethargy last anywhere from an hour to 10 days. An affected person may vomit several times per hour, potentially leading to a dangerous loss of fluids (dehydration). Additional symptoms can include unusually pale skin (pallor), abdominal pain, diarrhea, headache, fever, and an increased sensitivity to light (photophobia) or to sound (phonophobia). In most affected people, the signs and symptoms of each attack are quite similar. These attacks can be debilitating, making it difficult for an affected person to go to work or school.

Episodes of nausea, vomiting, and lethargy can occur regularly or apparently at random, or can be triggered by a variety of factors. The most common triggers are emotional excitement and infections. Other triggers can include periods without eating (fasting), temperature extremes, lack of sleep, overexertion, allergies, ingesting certain foods or alcohol, and menstruation.

If the condition is not treated, episodes usually occur four to 12 times per year. Between attacks, vomiting is absent, and nausea is either absent or much reduced. However, many affected people experience other symptoms during and between episodes, including pain, lethargy, digestive disorders such as gastroesophageal reflux and irritable bowel syndrome, and fainting spells (syncope). People with cyclic vomiting syndrome are also more likely than people without the disorder to experience depression, anxiety, and panic disorder. It is unclear whether these health conditions are directly related to nausea and vomiting.

Cyclic vomiting syndrome is often considered to be a variant of migraines, which are severe headaches often associated with pain, nausea, vomiting, and extreme sensitivity to light and sound. Cyclic vomiting syndrome is likely the same as or closely related to a condition called abdominal migraine, which is characterized by attacks of stomach pain and cramping. Attacks of nausea, vomiting, or abdominal pain in childhood may be replaced by migraine headaches as an affected person gets older. Many people with cyclic vomiting syndrome or abdominal migraine have a family history of migraines.

Most people with cyclic vomiting syndrome have normal intelligence, although some affected people have developmental delay or intellectual disability. Autism spectrum disorder, which affects communication and social interaction, have also been associated with cyclic vomiting syndrome. Additionally, muscle weakness (myopathy) and seizures are possible. People with any of these additional features are said to have cyclic vomiting syndrome plus.

Experts don’t know how common cyclic vomiting syndrome is in adults. However, experts believe that cyclic vomiting syndrome may be just as common in adults as in children. Doctors diagnose about 3 out of 100,000 children with cyclic vomiting syndrome every year.

People with cyclic vomiting syndrome may have other health problems, including

• migraines
• anxiety and depression
• gastroparesis
• autonomic nervous system disorders
• high blood pressure
• gastroesophageal reflux disease
• irritable bowel syndrome

The severe vomiting and retching that happen during cyclic vomiting episodes may cause the following complications:

• dehydration
• esophagitis
• Mallory-Weiss tears
• tooth decay or damage to tooth enamel

You may be more likely to get cyclic vomiting syndrome if you have

• migraines or a family history of migraines
• a history of long-term marijuana use
• a tendency to get motion sickness

Among adults with cyclic vomiting syndrome, about 6 out of 10 are Caucasian.

Experts aren’t sure what causes cyclic vomiting syndrome. However, some experts believe the following conditions may play a role:

• problems with nerve signals between the brain and digestive tract
• problems with the way the brain and endocrine system react to stress
• mutations in certain genes that are associated with an increased chance of getting CVS

The main symptoms of cyclic vomiting syndrome are sudden, repeated attacks—called episodes—of severe nausea and vomiting. You may vomit several times an hour. Episodes can last from a few hours to several days. Episodes may make you feel very tired and drowsy.

Each episode of cyclic vomiting syndrome tends to start at the same time of day, last the same length of time, and happen with the same symptoms and intensity as previous episodes. Episodes may begin at any time but often start during the early morning hours.

Other symptoms of cyclic vomiting syndrome may include one or more of the following:

• retching—trying to vomit but having nothing come out of your mouth, also called dry vomiting
• pain in the abdomen
• abnormal drowsiness
• pale skin
• headaches
• lack of appetite
• not wanting to talk
• drooling or spitting
• extreme thirst
• sensitivity to light or sound
• dizziness
• diarrhea
• fever

You should seek medical help if

• the medicines your doctor recommended or prescribed for the prodrome phase don’t relieve your symptoms
• your episode is severe and lasts more than several hours
• you are not able to take in foods or liquids for several hours

You should seek medical help right away if you have any signs or symptoms of dehydration during the vomiting phase. These signs and symptoms may include

• extreme thirst and dry mouth
• urinating less than usual
• dark-colored urine
• dry mouth
• decreased skin turgor, meaning that when your skin is pinched and released, the skin does not flatten back to normal right away
• sunken eyes or cheeks
• light-headedness or fainting

If you are a parent or caregiver of an infant or child, you should seek medical care for them right away if they have any signs and symptoms of dehydration during the vomiting phase. These signs and symptoms may include

• thirst
• urinating less than usual, or no wet diapers for 3 hours or more
• lack of energy
• dry mouth
• no tears when crying
• decreased skin turgor
• sunken eyes or cheeks
• unusually cranky or drowsy behavior

Triggers for an episode of cyclic vomiting may include:

• emotional stress
• anxiety or panic attacks, especially in adults
• infections, such as colds, flu, or chronic sinusitis
• intense excitement before events such as birthdays, holidays, vacations, and school outings, especially in children
• lack of sleep
• physical exhaustion
• allergies
• temperature extremes of hot or cold
• drinking alcohol
• menstrual periods
• motion sickness
• periods without eating (fasting)

Eating certain foods, such as chocolate, cheese, and foods with monosodium glutamate (MSG) may play a role in triggering episodes.

Cyclic vomiting syndrome has four phases:

• prodrome phase
• vomiting phase
• recovery phase
• well phase

The symptoms will vary as you go through the four phases of cyclic vomiting syndrome:

• Prodrome phase. During the prodrome phase, you feel an episode coming on. Often marked by intense sweating and nausea—with or without pain in your abdomen—this phase can last from a few minutes to several hours. Your skin may look unusually pale.
• Vomiting phase. The main symptoms of this phase are severe nausea, vomiting, and retching. At the peak of this phase, you may vomit several times an hour. You may be
  • quiet and able to respond to people around you
  • unable to move and unable to respond to people around you
  • twisting and moaning with intense pain in your abdomen

Nausea and vomiting can last from a few hours to several days.

• Recovery phase. Recovery begins when you stop vomiting and retching and you feel less nauseated. You may feel better gradually or quickly. The recovery phase ends when your nausea stops and your healthy skin color, appetite, and energy return.
• Well phase. The well phase happens between episodes. You have no symptoms during this phase.

Doctors diagnose cyclic vomiting syndrome based on family and medical history, a physical exam, pattern of symptoms, and medical tests. Your doctor may perform medical tests to rule out other diseases and conditions that may cause nausea and vomiting.

Family and medical history

Your doctor will ask about your family and medical history. He or she may ask for details about your history of health problems such as migraines, irritable bowel syndrome, and gastroparesis. Your doctor may also ask about your history of mental health problems, use of substances such as marijuana, and cigarette smoking.

Physical exam

During a physical exam, your doctor will

• examine your body
• check your abdomen for unusual sounds, tenderness, or pain
• check your nerves, muscle strength, reflexes, and balance

Pattern or cycle of symptoms in children

A doctor will often suspect cyclic vomiting syndrome in a child when all of the following are present:

• at least five episodes over any time period, or a minimum of three episodes over a 6-month period
• episodes lasting 1 hour to 10 days and happening at least 1 week apart
• episodes similar to previous ones, tending to start at the same time of day, lasting the same length of time, and happening with the same symptoms and intensity
• vomiting during episodes happening at least four times an hour for at least 1 hour
• episodes are separated by weeks to months, usually with no symptoms between episodes
• after appropriate medical evaluation, symptoms cannot be attributed to another medical condition

Pattern or cycle of symptoms in adults

A doctor will often suspect cyclic vomiting syndrome in adults when all of the following are present:

• three or more separate episodes in the past year and two episodes in the past 6 months, happening at least 1 week apart
• episodes that are usually similar to previous ones, meaning that episodes tend to start at the same time of day and last the same length of time—less than 1 week
• no nausea or vomiting between episodes, but other, milder symptoms can be present between episodes
• no metabolic, gastrointestinal, central nervous system, structural, or biochemical disorders

A personal or family history of migraines supports the doctor’s diagnosis of cyclic vomiting syndrome.

Your doctor may diagnose cyclic vomiting syndrome even if your pattern of symptoms or your child’s pattern of symptoms do not fit the patterns described here. Talk to your doctor if your symptoms or your child’s symptoms are like the symptoms of cyclic vomiting syndrome.

Doctors use lab tests, upper GI endoscopy, and imaging tests to rule out other diseases and conditions that cause nausea and vomiting. Once other diseases and conditions have been ruled out, a doctor will diagnose cyclic vomiting syndrome based on the pattern or cycle of symptoms.

Lab tests

Your doctor may use the following lab tests:

• Blood tests can show signs of anemia, dehydration, inflammation, infection, and liver problems.
• Urine tests can show signs of dehydration, infection, and kidney problems.

Blood and urine tests can also show signs of mitochondrial diseases.

Upper GI endoscopy

Your doctor may perform an upper GI endoscopy to look for problems in your upper digestive tract that may be causing nausea and vomiting.

Imaging tests

A doctor may perform one of more of the following imaging tests:

• Ultrasound of the abdomen.
• Gastric emptying test, also called gastric emptying scintigraphy. This test involves eating a bland meal, such as eggs or an egg substitute, that contains a small amount of radioactive material. An external camera scans the abdomen to show where the radioactive material is located. A radiologist can then measure how quickly the stomach empties after the meal. Health care professionals perform gastric emptying tests only between episodes.
• Upper GI series.
• MRI scan or CT scan of the brain.

Treatment of cyclic vomiting syndrome (CVS) aims to prevent episodes (prophylactic therapy), stop episodes (abortive therapy), and provide supportive care while symptoms are present (supportive therapy). There is no specific treatment that has been proven effective in controlled trials, but several therapies based on observation and experience (empiric therapies) have been effective in case series. Treatment options for each person may depend on the person's age, whether there is a family history of migraines, the severity of episodes, and how often episodes occur. People with CVS should consult with their doctor about a personalized treatment plan.

Prophylactic therapy options include:

• Avoiding triggers of episodes (e.g. certain foods, physical exhaustion, sleep deprivation, or psychological stress).
• Various medications (usually for patients with more than one episode per month). Examples include cyproheptadine, amitriptyline (a tricyclic antidepressant), various anti-convulsants, propranolol, and erythromycin. There is consensus among experts that amitriptyline should be used as the first treatment for children over 5 years old, and cyproheptadine for children under 5 years old. Approximately 80% of those with a family history of migraines respond well to anti-migraine medications.
• Supplements called coenzyme Q-10 and L-carnitine. Retrospective studies have shown these to be very effective.

Abortive therapy options include various anti-migraine and anti-nausea medications such as ondansetron, promethazine, prochlorperazine, and a group of drugs used for migraines called triptans (e.g. sumatriptan).Supportive therapy is needed when both prophylactic and abortive therapies are unsuccessful. Supportive care is an extremely important aspect of treatment while a person is having symptoms. This may involve:

• Oral fluids if possible.
• IV fluids if needed.
• Sedatives or pain medications to allow for sleep and a break from severe nausea.

How doctors treat cyclic vomiting syndrome depends on the phase. Your doctor may

• prescribe medicines
• treat health problems that may trigger the disorder
• recommend
  • staying away from triggers
  • ways to manage triggers
  • getting plenty of sleep and rest

Prodrome phase

Taking medicines early in this phase can sometimes help stop an episode from happening. Your doctor may recommend over-the-counter medicines or prescribe medicines such as

• ondansetron (Zofran) or promethazine (Phenergan) for nausea
• sumatriptan (Imitrex) for migraines
• lorazepam (Ativan) for anxiety
• ibuprofen for pain

Your doctor may recommend over-the-counter medicines to reduce the amount of acid your stomach makes, such as

• famotidine (Pepcid)
• ranitidine (Zantac)
• omeprazole (Prilosec)
• esomeprazole (Nexium)

Vomiting phase

During this phase, you should stay in bed and sleep in a dark, quiet room. You may have to go to a hospital if your nausea and vomiting are severe or if you become severely dehydrated. Your doctor may recommend or prescribe the following for children and adults:

• medicines for
  • nausea
  • migraines
  • anxiety
  • pain
• medicines that reduce the amount of acid your stomach makes

If you go to a hospital, your doctor may treat you with

• intravenous (IV) fluids for dehydration
• medicines for symptoms
• IV nutrition if an episode continues for several days

Recovery phase

During the recovery phase, you may need IV fluids for a while. Your doctor may recommend that you drink plenty of water and liquids that contain glucose and electrolytes, such as

• broths
• caffeine-free soft drinks
• fruit juices
• sports drinks
• oral rehydration solutions, such as Pedialyte

If you’ve lost your appetite, start drinking clear liquids and then move slowly to other liquids and solid foods. Your doctor may prescribe medicines to help prevent future episodes.

Well phase

During the well phase, your doctor may prescribe medicines to help prevent episodes and how often and how severe they are, such as

• amitriptyline (Elavil)
• cyproheptadine (Periactin)
• propranolol (Inderal)
• topiramate (Topamax)
• zonisamide (Zonegran)

Your doctor may also recommend coenzyme Q10, levocarnitine (L-carnitine), or riboflavin as dietary supplements to help prevent episodes.

Doctors treat the complications of cyclic vomiting syndrome as follows:

• dehydration—plenty of liquids with glucose and electrolytes; or IV fluids and hospitalization for severe dehydration
• esophagitis—medicines to reduce the amount of acid your stomach makes
• Mallory-Weiss tears—medicines or medical procedures to stop bleeding if the tears don’t heal on their own, which they generally do
• tooth decay or damage to tooth enamel—dental fillings, fluoride toothpaste, or mouth rinses

Knowing and managing your triggers can help prevent cyclic vomiting syndrome, especially during the well phase. You should also

• get enough sleep and rest
• treat infections and allergies
• learn how to reduce or manage stress and anxiety
• avoid foods and food additives that trigger episodes

Your diet will not help prevent or relieve episodes but will help you recover and keep you healthy.

Your doctor may recommend coenzyme Q10, levocarnitine (L-carnitine), or riboflavin as dietary supplements to help prevent episodes.

When your nausea and vomiting stop, you can generally go back to your regular diet right away. In some cases, you may want to start with clear liquids and go slowly back to your regular diet. You should eat well-balanced and nutritious meals between your episodes. Your doctors will recommend that you not skip meals in between episodes. If you are dehydrated, drink plenty of liquids that contain glucose and electrolytes, such as

• broths
• caffeine-free soft drinks
• fruit juices
• sports drinks
• oral rehydration solutions, such as Pedialyte

In between episodes, you should avoid eating foods that may have triggered past episodes. Eating certain foods such as chocolate, cheese, and foods with monosodium glutamate (MSG), may trigger an episode in some people. Adults should avoid drinking alcohol.