This is a medical question of type : exams and tests 
 How to diagnose Zollinger-Ellison Syndrome ? 
 A health care provider diagnoses Zollinger-Ellison syndrome based on the following:
                
- medical history   - physical exam  - signs and symptoms  - blood tests  - upper gastrointestinal (GI) endoscopy  - imaging tests to look for gastrinomas  - measurement of stomach acid
                
Medical History
                
Taking a medical and family history is one of the first things a health care provider may do to help diagnose Zollinger-Ellison syndrome. The health care provider may ask about family cases of MEN1 in particular.
                
Physical Exam
                
A physical exam may help diagnose Zollinger-Ellison syndrome. During a physical exam, a health care provider usually
                
- examines a persons body  - uses a stethoscope to listen to bodily sounds  - taps on specific areas of the persons body
                
Signs and Symptoms
                
A health care provider may suspect Zollinger-Ellison syndrome if
                
- diarrhea accompanies peptic ulcer symptoms or if peptic ulcer treatment fails.  - a person has peptic ulcers without the use of nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin and ibuprofen or a bacterial Helicobacter pylori (H. pylori) infection. NSAID use and H. pylori infection may cause peptic ulcers.  - a person has severe ulcers that bleed or cause holes in the duodenum or stomach.  - a health care provider diagnoses a person or the persons family member with MEN1 or a person has symptoms of MEN1.
                
Blood Tests
                
The health care provider may use blood tests to check for an elevated gastrin level. A technician or nurse draws a blood sample during an office visit or at a commercial facility and sends the sample to a lab for analysis. A health care provider will ask the person to fast for several hours prior to the test and may ask the person to stop acid-reducing medications for a period of time before the test. A gastrin level that is 10 times higher than normal suggests Zollinger-Ellison syndrome.2
                
A health care provider may also check for an elevated gastrin level after an infusion of secretin. Secretin is a hormone that causes gastrinomas to release more gastrin. A technician or nurse places an intravenous (IV) needle in a vein in the arm to give an infusion of secretin. A health care provider may suspect Zollinger-Ellison syndrome if blood drawn after the infusion shows an elevated gastrin level.
                
Upper Gastrointestinal Endoscopy
                
The health care provider uses an upper GI endoscopy to check the esophagus, stomach, and duodenum for ulcers and esophagitisa general term used to describe irritation and swelling of the esophagus. This procedure involves using an endoscopea small, flexible tube with a lightto see the upper GI tract, which includes the esophagus, stomach, and duodenum. A gastroenterologista doctor who specializes in digestive diseasesperforms the test at a hospital or an outpatient center. The gastroenterologist carefully 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. A person may receive a liquid anesthetic that is gargled or sprayed on the back of the throat. A technician or nurse inserts an IV needle in a vein in the arm if anesthesia is given.
                
Imaging Tests
                
To help find gastrinomas, a health care provider may order one or more of the following imaging tests:
                
- Computerized tomography (CT) scan. A CT scan is an x ray that produces pictures of the body. A CT scan may include the injection of a special dye, called contrast medium. CT scans use a combination of x rays and computer technology to create images. CT scans require the person to lie on a table that slides into a tunnel-shaped device where an x-ray technician takes x rays. A computer puts the different views together to create a model of the pancreas, stomach, and duodenum. The x-ray technician performs the procedure in an outpatient center or a hospital, and a radiologista doctor who specializes in medical imaginginterprets the images. The person does not need anesthesia. CT scans can show tumors and ulcers.  - Magnetic resonance imaging (MRI). MRI is a test that takes pictures of the bodys internal organs and soft tissues without using x rays. A specially trained technician performs the procedure in an outpatient center or a hospital, and a radiologist interprets the images. The person does not need anesthesia, though people with a fear of confined spaces may receive light sedation, taken by mouth. An MRI may include the injection of contrast medium. With most MRI machines, the person will lie on a table that slides into a tunnel-shaped device that may be open ended or closed at one end. Some machines allow the person to lie in a more open space. During an MRI, the person, although usually awake, remains perfectly still while the technician takes the images, which usually takes only a few minutes. The technician will take a sequence of images from different angles to create a detailed picture of the upper GI tract. During sequencing, the person will hear loud mechanical knocking and humming noises.  - Endoscopic ultrasound. This procedure involves using a special endoscope called an endoechoscope to perform ultrasound of the pancreas. The endoechoscope has a built-in miniature ultrasound probe that bounces safe, painless sound waves off organs to create an image of their structure. A gastroenterologist performs the procedure in an outpatient center or a hospital, and a radiologist interprets the images. The gastroenterologist carefully feeds the endoechoscope down the esophagus, through the stomach and duodenum, until it is near the pancreas. A person may receive a liquid anesthetic that is gargled or sprayed on the back of the throat. A sedative helps the person stay relaxed and comfortable. The images can show gastrinomas in the pancreas.  - Angiogram. An angiogram is a special kind of x ray in which an interventional radiologista specially trained radiologistthreads a thin, flexible tube called a catheter through the large arteries, often from the groin, to the artery of interest. The radiologist injects contrast medium through the catheter so the images show up more clearly on the x ray. The interventional radiologist performs the procedure and interprets the images in a hospital or an outpatient center. A person does not need anesthesia, though a light sedative may help reduce a persons anxiety during the procedure. This test can show gastrinomas in the pancreas.  - Somatostatin receptor scintigraphy. An x-ray technician performs this test, also called OctreoScan, at a hospital or an outpatient center, and a radiologist interprets the images. A person does not need anesthesia. A radioactive compound called a radiotracer, when injected into the bloodstream, selectively labels tumor cells. The labeled cells light up when scanned with a device called a gamma camera. The test can show gastrinomas in the duodenum, pancreas, and other parts of the body.
                
Small gastrinomas may be hard to see; therefore, health care providers may order several types of imaging tests to find gastrinomas.
                
Stomach-acid Measurement
                
Using a sample of stomach juices for analysis, a health care provider may measure the amount of stomach acid a person produces. During the exam, a health care provider puts in a nasogastric tubea tiny tube inserted through the nose and throat that reaches into the stomach. A person may receive a liquid anesthetic that is gargled or sprayed on the back of the throat. Once the tube is placed, a health care provider takes samples of the stomach acid. High acid levels in the stomach indicate Zollinger-Ellison syndrome.