What are the diagnostic criteria and treatment options for functional dyspepsia?

Functional Dyspepsia Syndromes and Diagnostic Criteria

Functional dyspepsia (FD) is diagnosed in patients with bothersome epigastric pain, epigastric burning, postprandial fullness, and/or early satiation of at least 8 weeks duration, in the absence of structural disease that would explain these symptoms. 1, 2

Definition and Classification

• FD is a common disorder of gut-brain interaction affecting approximately 7% of individuals in the community, with prevalence varying between countries (2.4% in Japan to 12.3% in Egypt) 1
• Most patients with dyspepsia (approximately 80%) will have FD as the underlying cause after investigation 1, 2
• According to Rome IV criteria, FD is classified into two distinct subtypes 1:
  • Postprandial Distress Syndrome (PDS)
  • Epigastric Pain Syndrome (EPS)

Diagnostic Criteria for Functional Dyspepsia

Rome IV Criteria

• Presence of one or more bothersome symptoms 1, 2:
  • Bothersome epigastric pain
  • Bothersome epigastric burning
  • Bothersome postprandial fullness
  • Bothersome early satiation
• Symptom onset at least 6 months prior to diagnosis 1, 2
• Symptoms active within the past 3 months 1, 2
• No evidence of structural disease (including at upper endoscopy) likely to explain the symptoms 1, 2

Clinical Criteria for Routine Practice

• The Rome Foundation has developed less restrictive "clinical criteria" that only require cardinal symptoms to have been present for 8 weeks 1
• This addresses concerns that the Rome IV 6-month requirement may delay diagnosis and treatment 1

Subtypes of Functional Dyspepsia

Epigastric Pain Syndrome (EPS)

• Must include one or both of the following symptoms at least 1 day a week 1, 2:
  • Bothersome epigastric pain (severe enough to impact usual activities)
  • Bothersome epigastric burning (severe enough to impact usual activities)
• Supportive criteria 1:
  • Pain may be induced by ingestion of a meal, relieved by ingestion of meal, or may occur while fasting
  • Postprandial epigastric bloating, belching, and nausea can also be present
  • Persistent vomiting likely suggests another disorder
  • Heartburn is not a dyspeptic symptom but may coexist
  • The pain does not fulfill biliary pain criteria
  • Symptoms relieved by evacuation of feces or gas generally should not be considered as part of dyspepsia
  • Other digestive symptoms (such as GERD and IBS) may coexist

Postprandial Distress Syndrome (PDS)

• Must include one or both of the following symptoms at least 3 days a week 1, 2:
  • Bothersome postprandial fullness (severe enough to impact usual activities)
  • Bothersome early satiation (severe enough to prevent finishing a regular-sized meal)
• Supportive criteria 1:
  • Postprandial epigastric pain or burning, epigastric bloating, excessive belching, and nausea can also be present
  • Vomiting warrants consideration of another disorder
  • Heartburn is not a dyspeptic symptom but may coexist
  • Symptoms relieved by evacuation of feces or gas should generally not be considered as part of dyspepsia
  • Other digestive symptoms (such as GERD and IBS) may coexist

Diagnostic Approach

• In patients without alarm symptoms or signs, FD can be diagnosed clinically based on characteristic symptoms 1
• A full blood count should be performed in patients aged ≥55 years with dyspepsia 1
• Coeliac serology should be checked in all patients with FD and overlapping IBS-type symptoms 1
• Urgent endoscopy is warranted in 1:
  • Patients aged ≥55 years with dyspepsia and weight loss
  • Patients aged >40 years from an area with increased risk of gastric cancer
  • Patients with a family history of gastro-oesophageal cancer
• Non-urgent endoscopy should be considered in patients aged ≥55 years with treatment-resistant dyspepsia or dyspepsia with either a raised platelet count or nausea or vomiting 1

Overlap with Other Conditions

• FD and gastroparesis have significant overlapping features and cannot be fully distinguished based on symptoms or gastric emptying studies alone 1, 2
• The term "FD with or without delayed gastric emptying" may be preferable to the term gastroparesis 1, 2
• FD can coexist with other digestive disorders including GERD and IBS 1, 3

Treatment Approaches

• Treatment may differ based on the predominant subtype 3, 4:
  • For EPS (epigastric pain/burning): acid-suppressive therapy with H2-receptor antagonists or proton pump inhibitors 5
  • For PDS (fullness/early satiety): prokinetic agents may be more effective 5, 6
• If initial treatment fails, switching therapy from proton pump inhibitor to prokinetic or vice versa can be tried 5
• Low-dose tricyclic antidepressants may help for visceral hypersensitivity 5, 6
• Lifestyle modifications including dietary changes (frequent small meals, low-fat diet) may improve symptoms 5

Clinical Pitfalls and Caveats

• Heartburn alone is not a symptom of dyspepsia, although it can coexist 1
• Vomiting is atypical in FD and should prompt consideration of another disorder 1
• Symptoms alone are not reliable in distinguishing functional from organic causes of dyspepsia 1
• Extensive or repetitive investigations have low diagnostic yield in the absence of localizing symptoms or alarm features 6
• Patients with FD can have overlapping features of EPS and PDS, particularly in secondary and tertiary care settings 1