Cyclic vomiting syndrome, or CVS, causes repeat episodes of severe vomiting. Between episodes, most children feel well again.

CVS is a brain-gut condition. It happens when signals between the brain and stomach do not work as they should. Many children with CVS also have migraines or a family history of migraines.

At Children's Wisconsin, our team cares for children with mild, moderate and severe CVS. This includes children with refractory vomiting or intractable vomiting, meaning vomiting that does not improve with standard treatment. Because CVS affects both the brain and the gut, care often works best when digestive, neurology and behavioral health experts work together.

Experts do not fully understand what causes CVS. Many believe it comes from changes in the brain-gut connection. Factors that may play a role or serve as triggers of episodes include:

• Migraine disorders
• Family history of migraines
• Stress or anxiety
• Viral illness
• Poor sleep
• Hormone changes
• Motion sickness
• Nervous system changes

There is no single test for CVS. Our team looks at your child's symptom pattern, medical history, migraine history and physical exam. We may also run tests to rule out other conditions.

Many children who are diagnosed with CVS have:

• Four or more vomiting episodes each year that last up to a week.
• Sudden onset of symptoms.
• Symptom-free periods between episodes.
• No other condition that explains the symptoms.

Nationally ranked: U.S. News & World Report consistently ranks our GI Program as among the nation’s best. We provide the best possible care for kids with brain-gut disorders. Our team of experts can help you and your family figure out your child’s condition.

Cyclic Vomiting Syndrome Program: The first and largest program of its kind in the world. We are experts in treating kids with severe, frequent vomiting episodes. Our program director is a leading expert in CVS. They authored the 2025 international guidelines for diagnosing and treating pediatric CVS.

Expert clinical care: Our pediatric GI team is well known as one of the largest and most well-rounded in the country. Our experts diagnose and treat digestive health issues of all kinds. Our care teams bring together the skills of experts across many areas.

Focus on kids: We know that kids need different care than adults. Our team at Children’s Wisconsin has expertise in managing diverse GI issues in infants, kids and teens. We take a whole-child approach to care. We’re always thinking about your child’s growth, physical and emotional development and age-related social issues.

Education and emotional support: We support your family at every stage of care. We teach you about your child’s digestive issues and explain what to expect. Our care team works with you and your family to manage the physical and emotional impacts of GI disease.