Functional Dyspepsia (FD)

Research

Prevalence

  • Dyspepsia common at 20%

  • 80% of patients with dyspepsia are eventually diagnosed as functional dyspepsia

  • Especially females, smokers, and people on NSAIDs

Epidemiology

  • 5 to 10% worldwide

Pathophysiology

  • Gastric emptying, accommodation, and vagal function

    • Associated with motility disorders

  • Visceral hypersensitivity

    • Lower threshold for the induction of pain in the presence of normal gastric compliance

  • Helicobacter pylori

  • Altered gut microbiome

  • Duodenal inflammatory and immune activation

    • Increased eosinophils and mast cells

  • HPA axis and stress

    • Increases salivary cortisol and intestinal permeability

  • Psychosocial dysfunction

    • FD linked to GAD, somatisation and MDD

Clinical manifestations

  • Postprandial fulness

  • Early satiety

  • Bloating

  • Epigastric pain or burning

  • Nausea

  • Vomiting

  • Heartburn

Diagnosis

  • Rome IV criteria

  • One or more of

    • postprandial fullness

    • early satiation

    • epigastric pain or epigastric burning

    • and no evidence of structural disease

  • Criteria should be fulfilled for the last three months with symptoms onset at least six months before diagnosis

Subtypes

  • Postprandial distress syndrome

    • Must include one or both of the following at least three days per week:

      1. Bothersome postprandial fullness (ie, severe enough to impact on usual activities)

      1. Bothersome early satiation (ie, severe enough to prevent finishing a regular-size meal)

      2. No evidence of organic, systemic, or metabolic disease that is likely to explain the symptoms on routine investigations (including at upper endoscopy)

  • Epigastric pain syndrome

    • Must include at least one of the following symptoms at least one day a week:

      1. Bothersome epigastric pain (ie, severe enough to impact on usual activities)

      AND/OR

      1. Bothersome epigastric burning (ie, severe enough to impact on usual activities)

      No evidence of organic, systemic, or metabolic disease that is likely to explain the symptoms on routine investigations (including at upper endoscopy)

Differential

  • Peptic ulcer disease

  • Helicobacter pylori gastritis

  • Gastroesophageal reflux disease (GERD)

  • Biliary pain

  • Chronic abdominal wall pain

  • Gastric or esophageal cancer

  • Gastroparesis

  • Pancreatitis

  • Carbohydrate malabsorption

  • Medications (including potassium supplements, digitalis, iron, theophylline, oral antibiotics [especially ampicillin and erythromycin], nonsteroidal anti-inflammatory drugs [NSAIDs], glucocorticoids, niacin, gemfibrozil, narcotics, colchicine, quinidine, estrogens, levodopa)

  • Infiltrative diseases of the stomach (eg, Crohn's disease, sarcoidosis)

  • Metabolic disturbances (hypercalcemia, hyperkalemia)

  • Hepatocellular carcinomaIschemic bowel disease, celiac artery compression syndrome, superior mesenteric artery syndrome

  • Systemic disorders (diabetes mellitus, thyroid, and parathyroid disorders, connective tissue disease)

  • Intestinal parasites (Giardia, Strongyloides)

  • Abdominal cancer, especially pancreatic cancer

Management

Management is controversial and alleviates symptoms in only a small proportion of patients

  • Test and treat H. Pylori

  • Trial PPI for 8 weeks

    • Effective in some patients with FD

    • RR = 0.88, NNT = 11

    • If effective attempt to discontinue every 6 to 12 months

  • H2 receptor antagonists

    • RRR = 23%, NNT = 7

  • Trial TCA as combination therapy

    • Amitriptyline 10mg at night, up titrate weekly intervals, to 20-30mg, adequate for most people

    • Trial 2 to 3 months before stopping if it is ineffective

    • If effective, continue for 6 months and consider tapering off

  • Mirtazapine has evidence

    • 7.5mg one hour before bed

    • Slow increase to 30 or 45mg

  • Prokinetics

    • If all above fails

    • Metoclopramide 5 to 10mg taken 30 minutes before meals

Therapies with an unclear or limited role

  • Psychotherapy

    • Possibly helpful in some patients

  • Fundic relaxants

    • Possible help e.g. Buspirone

  • Anti-nociceptive

    • e.g. Carbamazepine, Pregabalin

    • May decrease the central processing of pain and decrease visceral hypersensitivity

  • Complementary

    • Small benefit of peppermint oil

    • Small benefit STW5

  • Dietary modification

    • No link between various foods and FD disorders yet