Cyclical Vomiting Syndrome

Overview

Cyclical vomiting syndrome (CVS) is a condition that causes repeated, severe episodes of nausea and vomiting. The episodes come on suddenly, last for a few hours or sometimes a few days, and then stop completely. In between, the person usually feels completely well — often for weeks or even months at a time. It is not caused by a stomach bug or by something you ate that went off. Doctors believe it is linked to the way the brain and the gut communicate with each other, and it is closely related to migraine.

It is uncommon, but it is not rare. It is seen most often in children, although adults get it too. Many doctors think it is under-recognised, and it is often mistaken for 'one tummy bug after another', reflux, food poisoning, or a tummy sensitivity.

It can start at any age. It most often begins in childhood, usually between about 3 and 7 years old, and can carry on into adult life. In adults it is usually diagnosed in the 20s to 40s and is reported more often in women. Many people with cyclical vomiting syndrome also get migraines, or have close relatives who do.

Symptoms

Common symptoms

• Sudden, severe nausea followed by repeated vomiting — sometimes many times an hour.
• Tummy (abdominal) pain, which can be strong.
• Looking pale, sweating, and producing a lot of saliva.
• Headache, and being sensitive to light or sound.
• Feeling very tired, weak or 'washed out' during and just after an episode.
• Episodes that follow a similar pattern each time, often starting at night or early in the morning.
• Completely symptom-free stretches in between, which may last weeks or months.
• Some people feel a warning sign — such as nausea, sweating or stomach discomfort — an hour or two before the vomiting starts.

Symptoms in children

• Episodes often begin at night or in the early hours of the morning.
• A child may vomit many times, then fall into an exhausted sleep.
• Children often want to lie still in a dark, quiet room, and may not want to be touched or spoken to.
• Between episodes the child usually eats, plays, grows and gains weight normally.
• Parents often describe it as a tummy bug that 'keeps coming back' or 'happens every few weeks'.
• Young children may not be able to say they feel sick, and instead become pale, clingy and withdrawn.
• Episodes can lead to missed school days, which can affect schoolwork and friendships.

Symptoms in older adults

• Adults often have more tummy pain and may feel generally unwell, tired or low in between episodes.
• Episodes can be triggered by stress, poor sleep, travel or monthly periods.
• Older adults are at higher risk of dehydration, so fluid intake needs watching closely during episodes.
• In adults it is often mistaken for other conditions, such as gastroparesis (slow emptying of the stomach) or repeated infections.
• Weight loss, low energy and low vitamin levels can build up over time if episodes happen often.

Causes

Main causes

• The exact cause is not fully understood. Most experts believe it involves a problem in the way the brain and the gut signal to each other.
• It is very closely linked to migraine. Many people with cyclical vomiting syndrome get migraines themselves, or have close family members who do.
• Often no single trigger can be found, and episodes can happen without an obvious reason.
• In some people, heavy long-term cannabis (marijuana) use can cause a very similar pattern of repeated vomiting. Doctors call this cannabinoid hyperemesis, and they will usually ask about it because the advice and treatment are different.

Risk factors

• A personal history of migraine, or migraines in close family members.
• Being a child or teenager — it most often starts in childhood.
• A history of travel sickness or strong reactions to motion.
• Physical or emotional stress, excitement, or anxiety.
• Poor sleep or exhaustion.
• Skipping meals or going a long time without eating.
• Infections and viruses, which often set off the first episode.
• In some people, particular foods such as chocolate or cheese.
• Monthly periods in some women and girls.

When to see a doctor

See a doctor urgently if:

• Repeated vomiting that will not stop, or signs of dehydration such as dark urine, dizziness or drowsiness.
• Blood in the vomit, or vomit that looks like coffee grounds.
• Green or yellow-green vomit.
• Severe or worsening tummy pain.
• Vomiting after a head injury.
• A baby, young child or frail older adult who is becoming drowsy or difficult to rouse.

Book a routine appointment if:

• Repeated bouts of vomiting that come back every few weeks or months, especially if there is a clear pattern.
• Vomiting that has been put down to 'tummy bugs' several times but keeps returning.
• Episodes that are causing missed school or work, or affecting family life.
• Weight loss, poor appetite or low energy between episodes.
• A family history of migraine and repeated vomiting that has never been looked into.
• You feel anxious or low about the episodes, or you are not sure how to cope.

Diagnosis

There is no single test that proves cyclical vomiting syndrome. A doctor usually makes the diagnosis by listening carefully to the pattern of your symptoms — how often episodes happen, how long they last, what they look like, and whether you are completely well in between. They will also ask about migraines in you and your family, and about possible triggers. Because other conditions can look very similar, they will usually arrange some tests to rule those out first.

Tests that may be done

• A full history and physical examination, plus a careful review of a symptom diary if you have kept one.
• Blood tests to check salts (electrolytes), kidney function, blood sugar and, in some cases, hormone levels.
• A urine test, and in some cases a pregnancy test.
• Stool (poo) tests if an infection is suspected.
• An ultrasound scan of the tummy, especially in children and in anyone with pain.
• A camera test of the stomach (endoscopy) if there is pain, bleeding, weight loss or vomiting that is not typical.
• A scan of the brain (such as an MRI) in selected cases, if headaches or unusual nervous system signs are present.
• Tests for food allergies or coeliac disease if these are suspected.

What to expect at your appointment

The process can take a little time, and some people are seen more than once before the diagnosis is clear. Keeping a simple diary of episodes — dates, times, how long they lasted, what you ate or did beforehand, and how you felt — is one of the most helpful things you can bring to appointments. Write down any questions you have before you go in, and ask a relative or friend to come with you if that helps you remember what was said.

Treatment

There is no single cure, but cyclical vomiting syndrome can usually be managed well. Treatment has two aims: calming symptoms quickly during an episode, and reducing how often episodes happen. The most useful step for most people is a personal 'rescue plan' agreed with their doctor — a clear, written set of steps to start at the very first sign of an episode, before the vomiting becomes severe. Episodes that are caught early are usually shorter and easier.

Self-care at home

• At the first warning sign, stop and rest in a cool, dark, quiet room, away from strong smells and noise.
• Sip small amounts of fluid often — a spoonful at a time — rather than drinking a large glass. Sucking ice chips can help.
• If you can keep fluids down, try a simple rehydration drink from the pharmacy to replace salts and sugars.
• Once vomiting settles, restart eating gently with small amounts of plain, bland food, and build up slowly.
• Keep a simple diary of episodes and possible triggers so patterns become clearer over time.
• Protect sleep — try to keep regular bedtimes, as tiredness is a common trigger.
• Rinse your mouth with water after vomiting to protect your teeth, and avoid brushing straight away.
• Make a written plan with your family, school or workplace so everyone knows what to do when an episode starts.

Medical treatments

Doctors treat cyclical vomiting syndrome in two ways. First, 'during an episode' treatment: medicines that reduce nausea and vomiting, and medicines used for migraine, which can shorten an attack — these work best when started early. Some people also need fluids given through a drip if they become dehydrated, so it is worth knowing where to go for this. Second, 'preventive' treatment: if episodes are frequent or severe, your doctor may discuss a daily medicine used for migraine prevention, or vitamin and mineral supplements, which help some people. Your doctor will go through the pros and cons with you and find what suits you, because response varies a lot from person to person. Never start, stop or change any medicine without talking to your doctor or pharmacist first.

When is surgery considered?

Surgery is not a treatment for cyclical vomiting syndrome. Occasionally a camera test or scan is done to rule out other conditions, but these are checks rather than operations to treat the condition.

Living with this condition

Life with cyclical vomiting syndrome works best when you are prepared rather than surprised. Most people find that the unpredictable nature is the hardest part at first. Once you have a plan, a diary and a good relationship with a doctor who knows your pattern, daily life becomes much more manageable. Tell the people around you — family, teachers, managers, coaches — what an episode looks like and what helps, so you are not having to explain it in the middle of one.

Lifestyle tips

• Keep regular meal times and avoid long gaps without food.
• Aim for consistent, adequate sleep — this is one of the strongest triggers people report.
• Notice and manage stress where you can; relaxation, breathing exercises or talking therapy help some people.
• Keep a simple trigger diary for a few months to spot personal patterns.
• Avoid known triggers where practical, but do not let the condition shrink your life more than necessary.
• Stay hydrated day to day, and be extra careful in hot weather or during exercise.
• Have a small 'episode kit' ready at home and in your bag — a rehydration drink, a bucket, wipes and your written plan.

Diet and exercise

There is no special diet that cures cyclical vomiting syndrome, but eating regularly and not skipping meals helps many people. Some find that particular foods — commonly chocolate, cheese or foods containing monosodium glutamate (a flavour enhancer) — seem to set off episodes, but this varies. Instead of cutting out many foods at once, try keeping a diary and only remove foods that clearly cause problems, ideally with advice from a dietitian so you do not miss out on nutrients. Gentle, regular exercise such as walking or swimming is helpful for general wellbeing and stress, and is safe between episodes. During an episode, rest is more important than exercise, and you should build activity back up slowly afterwards.

Mental health and emotional wellbeing

Living with unpredictable vomiting can be genuinely hard emotionally. Many people feel anxious about when the next episode will come, worry about missing school or work, or feel embarrassed. Children may become fearful of school, and parents often feel helpless and exhausted. These feelings are common and worth mentioning to your doctor — talking therapies, support groups and practical planning all help. If you or someone you care for is having thoughts of self-harm or suicide, contact your local emergency number or a local crisis line straight away, and stay with someone you trust until you get help.

Prevention

You cannot always prevent cyclical vomiting syndrome, and episodes may still happen even with good care. But many people noticeably reduce how often episodes occur by avoiding their personal triggers, keeping regular meals and sleep, learning to start their rescue plan at the earliest warning sign, and — for some — using preventive treatment recommended by their doctor.

Screening programmes

There is no screening programme for cyclical vomiting syndrome. Because it is linked to migraine, it is worth telling your doctor if you have repeated vomiting episodes and a family history of migraine, so the pattern can be looked at properly.

Complications

If left untreated

• Dehydration, which can become serious, especially in young children and older adults.
• An imbalance in the body's salts (electrolytes), which can cause weakness, cramps or an irregular heartbeat in severe cases.
• Weight loss and poor growth in children if episodes are frequent.
• Damage to the enamel of the teeth from repeated contact with stomach acid.
• A small tear in the food pipe from forceful vomiting, which can cause streaks of blood (this is uncommon and usually heals).
• Missed school, work and social events, which can affect education, income and confidence.
• Anxiety and low mood, both for the person with the condition and for family members caring for them.
• Repeated tests and hospital visits before the diagnosis is recognised.

Long-term outlook

The outlook is generally good. Many children with cyclical vomiting syndrome improve or grow out of it as they get older, and many adults find episodes become less frequent or easier to handle once they have a diagnosis and a plan. It is a condition to manage rather than a dangerous one, and the great majority of people are able to live full lives with it. Getting the diagnosis right, learning your triggers and starting treatment early are the steps that make the biggest difference.

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