Cyclical vomiting syndrome unrelated to migraine

This code identifies a chronic, functional gastrointestinal disorder characterized by recurrent, stereotypical episodes of intense nausea and vomiting, separated by symptom-free intervals. These episodes can last for hours or days and are not attributable to other medical conditions or substance use.

Apply this code when documentation clearly indicates a diagnosis of cyclical vomiting syndrome where migraine has been explicitly ruled out as the underlying cause. This diagnosis is typically made based on clinical criteria including the characteristic pattern of severe vomiting attacks and the absence of other etiologies.

• Ensure documentation specifies "unrelated to migraine" to differentiate from G43.A-.
• Do not use if the vomiting is a symptom of bulimia nervosa or diabetes mellitus, as these conditions have specific Excludes2 notes.
• Look for physician notes detailing the episodic nature, severity, and symptom-free periods consistent with cyclical vomiting syndrome.