Zollinger‑Ellison syndrome – severe heartburn - Causes, Treatment & When to See a Doctor

Although ZES accounts for less than 1 % of all peptic ulcer disease, its hallmark symptom—persistent, burning heartburn that does not improve with over‑the‑counter antacids—should raise suspicion, especially when accompanied by multiple ulcers or ulcer disease that relapses quickly.

Sources: Mayo Clinic; National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK); American College of Gastroenterology.

Common Causes

Severe heartburn in ZES is driven by the underlying tumor, but several related conditions can mimic or exacerbate the symptom. The most frequent contributors include:

• Gastrinomas – neuroendocrine tumors that overproduce gastrin (primary cause of ZES).
• Multiple endocrine neoplasia type 1 (MEN‑1) – a genetic syndrome that often includes gastrinomas.
• Helicobacter pylori infection – can increase gastric acid output and worsen heartburn.
• Non‑steroidal anti‑inflammatory drugs (NSAIDs) – irritate the stomach lining and amplify acid‑related symptoms.
• Chronic gastro‑esophageal reflux disease (GERD) – may coexist and mask ZES‑related heartburn.
• Other functional neuroendocrine tumors – e.g., somatostatin‑producing (somatostatinomas) that alter acid regulation.
• Pancreatic or duodenal adenocarcinoma – rare but can produce ectopic gastrin.
• Zollinger‑Ellison syndrome secondary to sporadic (non‑familial) gastrinomas.
• Autoimmune gastritis – can lead to hypergastrinemia, though usually with low acid.
• Alcohol use disorder – stimulates gastrin release and impairs mucosal defenses.

Associated Symptoms

Patients with ZES often present with a cluster of gastrointestinal complaints that stem from the excessive acid load:

• Recurrent or multiple peptic ulcers – especially in the duodenum, jejunum, or beyond the duodenum (unusual locations).
• Abdominal pain – may be epigastric, cramping, or colicky.
• Diarrhea or steatorrhea – acid inactivates pancreatic enzymes, leading to malabsorption.
• Weight loss – due to malabsorption, anorexia, or chronic discomfort.
• Nausea and vomiting – occasionally with bile‑stained vomitus if the duodenum is ulcerated.
• Fatigue – from anemia secondary to chronic bleeding ulcers.
• Gastrointestinal bleeding – melena or hematemesis in severe ulcer disease.
• Bone pain or fractures – long‑standing hypergastrinemia can trigger osteoclastic activity.

When to See a Doctor

Because ZES can lead to serious complications, prompt medical evaluation is essential when any of the following occur:

• Heartburn that persists despite daily use of proton‑pump inhibitors (PPIs) or H2‑blockers.
• Frequent or recurrent ulcers (more than two within a year) or ulcers that fail to heal.
• Unexplained weight loss, persistent diarrhea, or greasy stools.
• Bleeding signs such as black stools, vomiting blood, or anemia‑related fatigue.
• Family history of MEN‑1 or known endocrine tumors.

Early referral to a gastroenterologist can prevent complications and guide appropriate testing.

Diagnosis

Diagnosing ZES involves confirming hypergastrinemia, ruling out other causes of elevated gastrin, and localizing the gastrinoma.

Laboratory Tests

• Fasting serum gastrin level – values >1000 pg/mL are highly suggestive, but levels >200 pg/mL with low gastric pH are also diagnostic.
• Secretin stimulation test – paradoxical rise in gastrin after intravenous secretin is characteristic of gastrinomas.
• Gastric pH measurement – a pH <2 supports acid hypersecretion.
• Complete blood count (CBC) – to assess anemia.
• Serum calcium and parathyroid hormone – screening for MEN‑1.

Imaging Studies

• Endoscopic ultrasound (EUS) – highly sensitive for small pancreatic/duodenal lesions.
• Multiphasic contrast‑enhanced CT or MRI – evaluates tumor size, location, and metastasis.
• Somatostatin receptor scintigraphy (Octreoscan) or Ga‑68 DOTATATE PET/CT – detects neuroendocrine tumors with high specificity.
• Upper endoscopy (EGD) – visualizes ulcers and may obtain biopsies to exclude malignancy.

Additional Evaluation

If MEN‑1 is suspected, genetic counseling and testing for mutations in the MEN1 gene are recommended.

Treatment Options

Therapy for ZES is two‑pronged: control of gastric acid and management of the gastrinoma itself.

Medical Management of Acid Hypersecretion

• Proton‑pump inhibitors (PPIs) – high‑dose omeprazole, esomeprazole, or rabeprazole are the mainstay; doses often exceed standard GERD regimens.
• H2‑blockers – may be added if PPIs alone are insufficient.
• Antacids – provide symptomatic relief but do not replace PPIs.
• Regular monitoring of serum gastrin and gastric pH to ensure adequate suppression.

Surgical Treatment of the Tumor

• Curative resection – for localized gastrinomas, pancreaticoduodenectomy or enucleation can be curative.
• Debulking surgery – in metastatic disease, reducing tumor burden can improve symptom control.
• Management of metastases – hepatic metastases may be addressed with radiofrequency ablation, embolization, or liver‑directed therapies.

Systemic Therapies

• Somatostatin analogs (octreotide, lanreotide) – inhibit gastrin release and may shrink tumor size.
• Targeted therapies – everolimus or sunitinib for progressive neuroendocrine tumors.
• Chemotherapy – reserved for high‑grade, rapidly progressive disease.

Home and Lifestyle Measures

• Take PPIs exactly as prescribed (usually 30 min before meals).
• Avoid trigger foods: caffeine, chocolate, citrus, tomato‑based products, spicy or fatty meals.
• Quit smoking and limit alcohol intake, both of which increase acid secretion.
• Eat smaller, more frequent meals and avoid lying flat for at least 2 hours after eating.
• Maintain a healthy weight to reduce intra‑abdominal pressure.

Prevention Tips

While the development of gastrinomas cannot be prevented in most cases, certain strategies can reduce the risk of complications and may delay disease progression:

• Screen high‑risk families – relatives of patients with MEN‑1 should undergo periodic serum gastrin testing and imaging.
• Prompt treatment of H. pylori – eradication reduces overall ulcer burden.
• Regular surveillance – once diagnosed, annual imaging and gastrin level checks help detect recurrence early.
• Adherence to acid‑suppression therapy – prevents ulcer formation and malabsorption.
• Balanced diet rich in fiber and low in processed fats – supports gut health and may lessen symptom severity.

Emergency Warning Signs