This is a medical question of type : exams and tests 
 How to diagnose Cyclic Vomiting Syndrome ? 
 A specific test to diagnose cyclic vomiting syndrome does not exist; instead, a health care provider will rule out other conditions and diagnose the syndrome based upon
                
- a medical and family history  - a physical exam  - a pattern or cycle of symptoms  - blood tests  - urine tests  - imaging tests  - upper GI endoscopy  - a gastric emptying test
                
Often, it is suspected that one of the following is causing their symptoms:
                
- gastroparesisa disorder that slows or stops the movement of food from the stomach to the small intestine  - gastroenteritisinflammation of the lining of the stomach, small intestine, and large intestine
                
A diagnosis of cyclic vomiting syndrome may be difficult to make until the person sees a health care provider. A health care provider will suspect cyclic vomiting syndrome if the person suffers from repeat episodes of vomiting.
                
Medical and Family History
                
Taking a medical and family history is one of the first things a health care provider may do to help diagnose cyclic vomiting syndrome. He or she will ask the patient to provide a medical and family history.
                
Physical Exam
                
A physical exam may help diagnose other conditions besides cyclic vomiting syndrome. During a physical exam, a health care provider usually
                
- examines a patients body  - taps on specific areas of the patients body
                
Pattern or Cycle of Symptoms in Children3
                
A health care provider will often suspect cyclic vomiting syndrome in a child when the child
                
- has at least five separate episodes, or at least three separate episodes over 6 months  - has episodes of intense nausea and vomiting lasting 1 hour to 10 days and occurring at least 1 week apart  - has episodes that are similar to previous onesthey tend to start at the same time of day, last the same length of time, and occur with the same symptoms and level of intensity  - vomits during episodes at least four times per hour for at least 1 hour  - vomits and it is not attributed to another disorder  - has absence of nausea and vomiting between episodes
                
Pattern or Cycle of Symptoms in Adults4,5
                
A health care provider will often suspect cyclic vomiting syndrome in adults when the following is present for at least 3 months and the symptoms started more than 6 months ago:
                
- Each episode of cyclic vomiting syndrome is usually similar to previous ones, meaning that episodes tend to start at the same time of day and last the same length of timeless than 1 week.  - Three or more separate episodes in the past year.  - Absence of nausea or vomiting between episodes.
                
Blood Tests
                
A nurse or technician will draw blood samples at a health care providers office or a commercial facility and send the samples to a lab for analysis. The blood test can tell the health care provider if the patient has any signs of dehydration or other problems.
                
Urine Tests
                
Urinalysis involves testing a urine sample. The patient collects a urine sample in a special container in a health care providers office or a commercial facility. A health care provider tests the sample in the same location or sends the sample to a lab for analysis. A urinalysis can rule out kidney problems or an infection.
                
Imaging Tests
                
The health care provider decides which test to order based on the symptoms, medical history, and physical exam.
                
Upper GI series. A health care provider may order an upper GI series to look at the upper GI tract. A radiologista doctor who specializes in medical imagingperforms this test at a hospital or an outpatient center. This test does not require anesthesia. The patient should not eat or drink for 8 hours before the procedure, if possible. During the procedure, the patient will stand or sit in front of an x-ray machine and drink barium, a chalky liquid. Infants lie on a table and a health care provider gives them barium through a tiny tube placed in the nose that runs into the stomach. Barium coats the GI tract, making signs of obstruction or other problems that can cause vomiting show up more clearly on x rays. A patient may experience bloating and nausea for a short time after the test. The upper GI series can show other problems that may be causing symptoms, such as an ulcer or obstruction.
                
Abdominal ultrasound. A health care provider may order an ultrasound to look at the organs in the abdomen. A technician uses a device, called a transducer, that bounces safe, painless sound waves off organs to create an image of their structure. The technician performs the procedure in a health care providers office, an outpatient center, or a hospital. A radiologist interprets the images. A patient does not need anesthesia. The abdominal ultrasound can show other problems that may be causing symptoms, such as gallstones.
                
Upper Gastrointestinal Endoscopy
                
This procedure involves using an endoscopea small, flexible tube with a lightto see the upper GI tract. A gastroenterologista doctor who specializes in digestive diseasesperforms the test at a hospital or an outpatient center. A health care provider may give a patient a liquid anesthetic to gargle or may spray anesthetic on the back of the patients throat. A nurse or technician will place an IV needle in a vein in the arm to administer sedation or anesthesia. Sedatives or anesthesia help a patient stay relaxed and comfortable. The gastroenterologist carefully inserts the endoscope into the mouth and feeds the endoscope down the esophagus and into the stomach and duodenum. A small camera mounted on the endoscope transmits a video image to a monitor, allowing close examination of the intestinal lining. The upper GI endoscopy can show other problems that may be causing symptoms, such as an ulcer. A gastroenterologist may obtain a biopsya procedure that involves taking a small piece of tissue for examination with a microscopeof the small-intestinal lining during an upper GI endoscopy. The patient will not feel the biopsy.
                
Gastric Emptying Test
                
Also called gastric emptying scintigraphy, this test involves eating a bland mealsuch as eggs or an egg substitutethat contains a small amount of radioactive material. A specially trained technician performs the test in a radiology center or hospital, and a radiologist interprets the results; the patient does not need anesthesia. An external camera scans the abdomen to show where the radioactive material is located. The radiologist is then able to measure the rate of gastric emptying at 1, 2, 3, and 4 hours after the meal.