What is the diagnostic approach for a patient with a suspected stomach ulcer?

Diagnostic Approach for Stomach Ulcer

For uncomplicated peptic ulcer disease presenting with epigastric pain, perform endoscopy as the definitive diagnostic test, while for suspected perforated ulcer with acute abdomen, obtain CT scan immediately as first-line imaging. 1, 2

Clinical Presentation to Recognize

Uncomplicated Ulcer

• Epigastric pain relieved by food or antacids, pain between meals or awakening at night, loss of appetite, and weight loss are the characteristic symptoms 3
• Approximately 10% of patients with upper abdominal pain in primary care have peptic ulcer as the cause 2
• Two-thirds of patients with peptic ulcer disease are asymptomatic, making clinical suspicion crucial 4

Complicated Ulcer (Perforation)

• Sudden onset of severe abdominal pain with tachycardia and abdominal rigidity is the hallmark presentation 5
• Critical pitfall: Physical examination may be equivocal and peritonitis present in only two-thirds of patients, particularly with contained or sealed perforations 1, 5

Diagnostic Algorithm

Step 1: Initial Assessment and Laboratory Studies

• Obtain complete blood count, metabolic panel, and arterial blood gas in patients with acute presentation suggesting complications 1, 6
• Leukocytosis, metabolic acidosis, and elevated serum amylase suggest perforation but are non-specific 1, 6
• These tests assess severity but do not confirm ulcer diagnosis 6

Step 2: Imaging Strategy (Based on Clinical Presentation)

For Suspected Perforation (Acute Abdomen):

• CT scan is strongly recommended as first-line imaging (Strong recommendation, 1C) 7, 1
• CT findings include pneumoperitoneum, unexplained intraperitoneal fluid, bowel wall thickening, mesenteric fat streaking, and extraluminal contrast 1
• If CT unavailable, perform chest/abdominal X-ray (erect or left lateral decubitus) as initial assessment (Strong recommendation, 1C) 7, 1
• Free air on X-ray ranges 30-85% sensitivity, making negative X-ray insufficient to rule out perforation 1
• When imaging is negative but suspicion persists, administer water-soluble contrast orally or via nasogastric tube (Weak recommendation, 2D) 7, 1
• Up to 12% of perforations have normal CT scan; triple contrast CT improves sensitivity in this scenario 1

For Uncomplicated Ulcer (Dyspepsia):

• Endoscopy definitively diagnoses peptic ulcer disease and is the most useful diagnostic procedure 2, 8
• Older patients and those with alarm symptoms (bleeding, weight loss, anemia, dysphagia) require prompt endoscopy 3
• Younger patients without alarm symptoms can follow test-and-treat strategy based on H. pylori testing before endoscopy 3
• All gastric ulcers require biopsy and histological examination to exclude malignancy 9

Step 3: H. pylori Testing (Mandatory in All Cases)

• All patients with suspected or confirmed gastric ulcer must undergo H. pylori testing 6
• Urea breath test has 88-95% sensitivity and 95-100% specificity for active infection 6
• Stool antigen test has 94% sensitivity and 92% specificity 6
• Stop PPIs, antibiotics, and bismuth for at least 2 weeks before testing to avoid false-negatives 6
• Do not rely on serology alone for treatment decisions as it cannot confirm active infection 6
• H. pylori infection causes approximately 42% of peptic ulcer disease cases 2

Step 4: Risk Stratification for Complicated Cases

• Apply Boey, PULP, or ASA scoring systems to predict outcomes in perforated peptic ulcer (Weak recommendation, 2C) 1
• Hypoalbuminemia is the strongest single predictor of mortality 1

Common Pitfalls to Avoid

• Never assume absence of peritonitis rules out perforation—one-third of perforations lack peritoneal signs 1, 5
• Never rely on X-ray alone when CT is available—CT has superior sensitivity for detecting perforation 7, 1
• Never skip biopsy of gastric ulcers—malignancy must be excluded histologically 9
• Never perform H. pylori testing while patient is on PPIs—this is the most common cause of false-negative results 6
• Never forget that NSAIDs cause approximately 36% of peptic ulcer disease—obtain detailed medication history 2