Functional Dyspepsia: Causes, Symptoms & Management

Functional dyspepsia (FD) is a disorder of gut-brain interaction (DGBI) characterized by chronic or recurrent upper abdominal symptoms without structural disease on endoscopy. It affects 10–20% of adults globally.

Pathophysiology (Multifactorial)

• Visceral Hypersensitivity: Lower pain threshold to gastric distension, acid, nutrients.
• Impaired Gastric Accommodation: Fundus fails to relax postprandially → early satiety, bloating.
• Delayed Gastric Emptying: ~30% have gastroparesis-like pattern (especially nausea/vomiting subtype).
• Duodenal Dysmotility & Eosinophilia: Altered feedback, low-grade inflammation.
• H. pylori: Eradication cures a subset ("H. pylori-associated dyspepsia").
• Psychosocial: Stress, anxiety, depression amplify gut-brain signaling (via vagus, HPA axis).
• Dietary Triggers: Fat, spice, alcohol, caffeine, FODMAPs.

Rome IV Diagnostic Criteria

≥1 of the following for ≥3 months (onset ≥6 months ago), no structural cause:

• Postprandial Distress Syndrome (PDS): Bothersome early satiety or postprandial fullness ≥3×/week.
• Epigastric Pain Syndrome (EPS): Bothersome epigastric pain/burning ≥1×/week, not exclusively postprandial.

Management (Stepwise)

1. H. pylori Test & Treat: Non-invasive (urea breath, stool Ag). Eradicate if positive.
2. Lifestyle/Diet: Small frequent meals, avoid triggers, weight loss if overweight, smoking cessation, stress management (CBT, gut-directed hypnotherapy).
3. First-Line Meds (4–8 week trial):
   • PPI (omeprazole 20 mg daily) — best for EPS.
   • Prokinetic (acotiamide, mosapride, domperidone) — for PDS/early satiety.
4. Second-Line:
   • Tricyclic antidepressant (amitriptyline 10–25 mg HS) — neuromodulation for visceral pain.
   • SSRI/SNRI if comorbid anxiety/depression.
   • Rifaximin (if SIBO suspected).
5. Refractory: Neuromodulators (gabapentinoids), psychological therapies, specialist referral.

FD is a diagnosis of exclusion—always rule out ulcer, cancer, GERD, gastroparesis, biliary disease first. A positive therapeutic trial supports the diagnosis. Shared decision-making and realistic expectations improve adherence and outcomes.