Cyclical vomiting syndrome

What is cyclical vomiting syndrome?

Cyclical vomiting syndrome is a condition in which a person has repeated episodes of feeling nauseous, vomiting and sometimes feeling exhausted. In between these episodes they will feel completely well.

The exact number of people with cyclical vomiting syndrome is not known. It is a rare condition and some experts state it affects around 3 in 100,000 children, although it is thought to be more common than this, possibly up to 2 in 100 children. It most commonly starts between the ages of 3 and 7 years and it is more common in girls than in boys.

Although it is more common in childhood, it also affects adults. It is more common in people who also have migraines. It can run in some families.

What are the symptoms of cyclical vomiting syndrome?

The main symptoms of cyclical vomiting syndrome are:

• Suddenly feeling severe nausea, then vomiting.

• It may cause tiredness before the nausea start.

• Abdominal pain and lack of appetite may also occur.

• Less frequently diarrhoea and headaches may also occur.

• These symptoms can last for a few hours to even a few days. They may require time off work or school.

What are the 4 phases of cyclical vomiting syndrome?

There are four phases of this condition:

• Prodromal phase - this involves severe sweating and feeling very sick. People often look very pale during this phase.

• Vomiting phase - when vomiting starts it is often very severe; being sick five to six times an hour is not unusual. Other symptoms such as those listed above may also occur.

• Recovery phase - the nausea and vomiting stop and the other symptoms resolve.

• Well phase - this is the last phase in which people are completely well. This can last for several days, weeks or months.

Many people find that their symptoms usually last for the same length of time each episode.

Note: it is important to seek medical attention if there are any symptoms or signs of a severe lack of fluid in the body (dehydration). These may include having dark-coloured urine, not passing urine very often or having a very dry mouth and dry skin.

What causes cyclical vomiting syndrome?

The actual cause of cyclical vomiting syndrome is not known.

The relationship between cyclical vomiting syndrome and migraines is well recognised. Some studies have suggested a link between cyclical vomiting syndrome and autonomic disturbances or mitochondrial dysfunction.

There is also good evidence that repeated cannabis use can lead to cyclical vomiting syndrome - stopping it has been shown to improve symptoms.

Episodes can also triggered by specific events. Examples of these include:

• Stress.

• Anxiety.

• Infections.

• Certain foods (for example, chocolate or cheese).

• Having long periods of time without food or drink.

• Being in hot weather.

• Menstrual periods in some women.

• Doing too much exercise.

• Not having enough sleep.

How is cyclical vomiting syndrome diagnosed?

There is no specific test for cyclical vomiting syndrome. The diagnosis is made from symptoms. Often other causes will need to be excluded and therefore sometimes further investigations or tests will be recommended.

In children, this condition is often suspected when:

• There have been five or more episodes ever or there have been at least three episodes in the previous six months.

• The episodes of being sick (vomiting) last between one hour and ten days and are at least one week apart.

• These vomiting episodes occur at least four times an hour for at least one hour.

• The child is completely well in between these episodes.

In adults, this condition is suspected when there have been three or more vomiting episodes in the previous year which have been very similar in nature.

Further investigations may include blood and urine tests. An ultrasound scan or a gastroscopy may be undertaken for some people. A gastroscopy is a test in which a thin, flexible telescope is passed down the oesophagus into the stomach.

Cyclical vomiting syndrome treatment

The treatment depends on the frequency and severity of the symptoms. Some are aware that an episode is going to start; the prodromal phase acts as a warning. It can be very useful to take treatment early to prevent an episode actually occurring.

Commonly a combination of medication is given. Medicine that helps to reduce feeling sick (nausea) and being sick (vomiting) and painkillers are often given. Sometimes certain medicines that are used for treating migraines can work really well.

If the nausea and vomiting are very severe and cause dehydration, hospital treatment is sometimes needed. Fluids and medicines can be given via a drip directly into a veins until the symptoms settle.

Preventing cyclical vomiting syndrome episodes

It is very important to try to recognise any triggers and then to avoid them, if possible.

If you are under any stress or have any anxiety then it is often worthwhile exploring treatments for these. See separate leaflets called Anxiety and Stress management for more details.

Eating regularly and getting enough sleep can help. Stopping cannabis is important as this has been shown to help.

Some people take medicines which are also given to prevent migraines occurring; there is no clear evidence of benefit but some people seem to respond very well to these.