Cyclic vomiting syndrome

Cyclic vomiting syndrome (CVS) is a disorder characterized by recurrent, sudden, and intense episodes of vomiting. The cause of CVS is unknown, but it's thought to be related to problems with the autonomic nervous system (the part of the nervous system that controls involuntary activities such as heart rate, digestion, and urination). CVS usually starts in childhood, mainly affecting children between the age of 3 to 7 years. It often resolves by adolescents, but it may persist in some individuals until adulthood.