How can I differentiate gastritis, functional dyspepsia, and acid peptic disease and what are the first‑line treatment options?

Differentiating Gastritis, Functional Dyspepsia, and Acid Peptic Disease

The key distinction is that functional dyspepsia (FD) is a clinical diagnosis made when upper abdominal symptoms persist despite normal endoscopy and testing, while gastritis and acid peptic disease (peptic ulcer disease) are endoscopic/histologic diagnoses requiring visualization of mucosal inflammation or ulceration. 1

Clinical Definitions and Differentiation

Functional Dyspepsia

• Symptom-based diagnosis consisting of chronic or recurrent upper abdominal pain/discomfort, early satiety, postprandial fullness, or epigastric burning that occurs without structural abnormalities on endoscopy 1
• Divided into two subtypes: Postprandial Distress Syndrome (PDS) with early satiety and postprandial fullness, and Epigastric Pain Syndrome (EPS) with epigastric pain or burning 2, 3
• Caused by gut-brain axis dysfunction, visceral hypersensitivity, impaired gastric accommodation, and sometimes delayed gastric emptying (30% of cases) 3
• Diagnosis of exclusion requiring endoscopy only in specific circumstances (see below) 2

Gastritis

• Endoscopic and histologic diagnosis showing mucosal inflammation on biopsy 1
• Often associated with H. pylori infection or NSAID use 1
• May be asymptomatic or present with dyspeptic symptoms indistinguishable from FD clinically 1
• Requires endoscopy with biopsies for definitive diagnosis 2

Acid Peptic Disease (Peptic Ulcer Disease)

• Endoscopic diagnosis showing discrete mucosal breaks (ulcers) in stomach or duodenum 1
• Accounts for approximately 10% of patients presenting with dyspeptic symptoms 1
• Primarily caused by H. pylori infection or NSAID use 1
• Requires endoscopy for diagnosis 1

Diagnostic Algorithm

When to Perform Endoscopy

Urgent endoscopy indications: 1

• Age ≥55 years with new-onset dyspepsia
• Alarm features: weight loss, dysphagia, persistent vomiting, evidence of GI bleeding, palpable mass, iron deficiency anemia
• Family history of gastric or esophageal cancer
• Treatment-resistant dyspepsia with raised platelet count or nausea/vomiting

Special consideration: 1

• Age ≥60 years with abdominal pain and weight loss requires urgent abdominal CT to exclude pancreatic cancer

For Patients NOT Requiring Immediate Endoscopy

The diagnostic approach is: 1, 2

1. Test for H. pylori using 13C-urea breath test or stool antigen test (not serology) 1, 2
2. If H. pylori positive: Provide eradication therapy first 1
3. If H. pylori negative OR symptoms persist after eradication: Diagnose as functional dyspepsia and proceed to treatment 1

Additional testing recommendations: 2

• Routine blood tests to exclude systemic diseases presenting with dyspeptic symptoms
• Do NOT routinely perform: abdominal ultrasound, celiac screening, gastric emptying studies, or 24-hour pH monitoring 1, 2

First-Line Treatment Options

For H. pylori-Positive Patients

Eradication therapy is the priority as it treats both peptic ulcer disease and can improve FD symptoms in a subset of patients 1, 2

• Provides symptom improvement in 24-82% of FD patients 4
• May prevent future gastric adenocarcinoma 1

For H. pylori-Negative Patients or Persistent Symptoms After Eradication

Proton Pump Inhibitors (PPIs) are first-line therapy: 1, 2, 5

• Strong recommendation for 4-8 weeks at standard dose (not high dose) 1, 2
• More effective than H2-receptor antagonists 4
• Response rate: 30-70%, with higher benefit in EPS subtype 4
• Use lowest effective dose that controls symptoms 1

Alternative first-line options based on symptom pattern: 2, 5

• For PDS (postprandial symptoms): Consider prokinetics, specifically acotiamide (acetylcholinesterase inhibitor) where available 5
• H2-receptor antagonists may be used but have weaker evidence than PPIs 1, 4

Lifestyle modifications: 1, 2

• Regular aerobic exercise (strong recommendation) 1
• Smaller, more frequent meals 3
• Avoid trigger foods 1
• Do NOT recommend restrictive diets (risk of malnutrition and disordered eating) 1, 2

Second-Line Treatment for Refractory Symptoms

Tricyclic Antidepressants (TCAs) as neuromodulators: 1, 2, 5

• Strong recommendation for refractory FD, particularly EPS 1
• Start amitriptyline 10 mg once daily, titrate slowly to 30-50 mg once daily 1
• Response rate: 27-71% 4
• Requires careful explanation of rationale (gut-brain neuromodulation, not depression treatment) 1

Alternative neuromodulators: 2, 5

• Mirtazapine: Recommended especially for patients with weight loss 2
• Antipsychotics (sulpiride, levosulpiride): May be efficacious but require careful counseling 1
• SSRIs are NOT recommended (insufficient evidence) 2

Prokinetics for PDS: 1, 2, 5

• Short course preferred for postprandial symptoms 1
• Options include acotiamide, itopride, mosapride (availability varies by region) 1

Behavioral therapies: 1, 2

• Cognitive behavioral therapy and hypnotherapy for patients not responding to medical therapy 2
• Address gut-brain axis dysfunction 1

Critical Pitfalls to Avoid

• Do not perform endoscopy in young patients (<45-55 years) without alarm features before trying H. pylori test-and-treat and empirical PPI therapy 1, 2
• Do not use high-dose PPIs when standard doses fail—this is not an effective strategy 2
• Screen for eating disorders (including ARFID) in patients with severe symptoms, weight loss, and food restriction 1
• Involve dietitian early in severe/refractory cases to prevent overly restrictive diets 1
• Confirm H. pylori eradication only in patients at increased risk for gastric cancer, not routinely 1
• Recognize GERD overlap: Patients with predominant heartburn (>1x/week) should be considered GERD, not dyspepsia 1