Zollinger-Ellison Syndrome (ZES) is a rare condition that affects the digestive tract. It’s characterized by the formation of tumors, called gastrinomas. Gastrinomas typically appear in the pancreas and upper part of the small intestine, also called the duodenum.

It’s possible to only have one tumor, but more common for there to be multiple ones.About half of these tumors are noncancerous, or benign.

Gastrinomas produce excessive amounts of a hormone called gastrin. Gastrin triggers an overproduction of gastric acid. Some gastric acid is necessary to help break down and digest food, but too much of it can lead to ulcers.

People with ZES are more at risk for the development of peptic ulcers than people without this syndrome. Peptic ulcers are painful sores in the lining of the digestive tract.

Read on to learn more about this condition.

Symptoms are generally digestive in nature. The two most common symptoms of ZES are abdominal pain and diarrhea. Other symptoms include:

ZES symptoms are sometimes confused with the more common peptic ulcer disease or gastroesophageal reflux disease gastroesophageal reflux disease (GERD). GERD is a chronic condition in which stomach acid backwashes into the esophagus. ZES symptoms tend to be more severe and less responsive to standard therapies than these other disorders.

Experts aren’t exactly sure what causes ZES. In most cases, the disorder appears for no obvious reason. In 25 percent of cases, it’s association with an inherited, tumor-causing condition called multiple endocrine neoplasia type 1 (MEN1).

More research is needed to better understand this condition.

ZES is extremely rare. It occurs in only 1 in 1 million people. It’s more common in men than women, and typically occurs between the ages of 30 and 50.

If your doctor suspects ZES, they will order a blood test to check for elevated levels of gastrin. If excessive gastrin is detected, imaging tests will be performed to determine the size and location of the gastrinomas. These tests can include:

  • CT scan
  • MRI scan
  • endoscopic ultrasound, which involves feeding a thin ultrasound probe down your throat

If you need an endoscopic ultrasound, your throat may be numbed with a liquid anesthetic, or you may receive light sedation in an outpatient center.

Other tests may involve using a contrasting dye that allows the tumors, which can be very small, to better show up on an X-ray or scan.

An upper gastrointestinal endoscopy, which involves threading a scope with a light and video camera down your throat while you’re sedated, can be used to take tissue samples to test for gastrinomas.

Your doctor may recommend a variety of treatments.

Proton pump inhibitors

Your doctor may prescribe drugs called proton pump inhibitors. These can be used to help reduce the amount of gastric acid that’s produced. That, in turn, can help the ulcers heal.

These drugs are generally given in much higher doses to people with ZES than to those who have ulcers without gastrinomas.

You’ll need careful monitoring while taking these drugs. Long-term use of proton pump inhibitors can increase your risk of hip, wrist, and spine fractures, especially after the age of 50.


In some cases, you may need surgery to remove the tumors. Surgery can be difficult because many gastrinomas are small, hard to locate, and present in multiples. Your doctor will discuss the specifics of your surgery if they decide you’re a candidate for this type of treatment.


Your doctor may also recommend treatments such as chemotherapy to shrink the tumors or radiofrequency ablation to kill off cells and stop growth of the tumors.

ZES is a rare but serious disease. Most ZES tumors grow slowly, and medications are very effective in reducing gastric acid and ulcer pain.

See your healthcare provider if you have digestive issues like diarrhea, heartburn, or abdominal pain lasting more than a few days. Early diagnosis and treatment can help stop the spread of any cancerous tumors.