I've heard different things. What exactly is cyclic vomiting?

Cyclic Vomiting. Cyclic vomiting syndrome (cvs) is ideopathic, characterized by intermittent attacks of nausea & vomiting which have no clear provoking or relieving factors. Each attack may last days, afterwhich the patient is symptom-free for months. Some sufferers exhibit delayed gastric emptying. Cvs is also considered one of several functional GI problems in children. Work-up is needed to find treatable issues.