and there are no diagnostic tests for CVS. Several other medical conditions, such as cannabinoid hyperemesis syndrome (CHS), can mimic the same symptoms, and it is important to rule these out. If all other possible causes have been excluded, a diagnosis of CVS using Rome criteria by a physician may be appropriate. Once formal investigations to rule out gastrointestinal or other causes have been conducted, these tests do not need to be repeated in the event of future episodes. Diagnostic criteria Due to the lack of specific biomarkers available for the disorder, and if all other possible causes can be ruled out (such as intestinal malrotation), physicians rely on the Rome IV process criteria in order to diagnose patients. Patients must meet all three of the following criteria to receive diagnosis: Stereotypical episodes of acute vomiting each with a duration of less than 1 week A history of at least three discrete episodes in the prior year and at least two episodes in the past 6 months, each occurring at least 1 week apart An absence of vomiting between episodes, but other milder symptoms can be present between cycles Criteria must be fulfilled for the last 3 months with symptom onset at least 6 months prior to diagnosis. A history of family history of migraine headaches can also be used in facilitating diagnosis. Treatment Treatment for cyclic vomiting syndrome depends on the evident phase of the disorder. Because the symptoms of CVS are similar (or perhaps identical) to those of the disease well-identified as "abdominal migraine," prophylactic migraine medications, such as topiramate and amitriptyline, have seen recent success in treatment for the prodrome and vomiting phases, reducing the duration, severity, and frequency of episodes. Therapeutic treatment for the prodromal phase, characterized by the anticipation of an episode, consists of sumatriptan (nasal or oral) an anti-migraine medication, anti-inflammatory drugs to reduce abdominal pain, and possible anti-emetic drugs. These options may be helpful in preventing an episode or reducing the severity of an attack. The most common therapeutic strategies for those already in the vomiting phase are maintenance of salt balance by appropriate intravenous fluids and, in some cases, sedation. Having vomited for a long period prior to attending a hospital, patients are typically severely dehydrated. For a number of patients, potent anti-emetic drugs such as ondansetron (Zofran) or granisetron (Kytril), and dronabinol (Marinol) may be helpful in either preventing an attack,