FUNCTIONAL DYSPEPSIA
1. DEFINITION
The word dyspepsia originates from the Greek (dys=bad and peptein= to digest) and the symptom was certainly familiar to the Greeks. In the first century A.D. Pliny recommended crushed coral for dyspepsia.
According to international consensus, (Rome II Working Party) functional dyspepsia is persistent or recurrent pain or discomfort centred in the upper abdomen without evidence of organic disease likely to explain the symptoms (1). It has also been styled nervous dyspepsia. The ICD 10AM Code is K31. It is characterised by bloating, nausea, early satiety, belching or upper abdominal fullness. There is overlap between functional dyspepsia and irritable bowel syndrome and so lower abdominal symptoms may also be present.
2. PREVALENCE
Functional dyspepsia affects between 20-54% of the adult population in western countries (2, 3). Most of these patients have no identifiable cause of dyspepsia by standard diagnostic tests and are classified as having functional dyspepsia (4). The overall prevalence of functional dyspepsia appears relatively stable but individually the disease is relapsing and remitting in nature (5).
3. NATURAL HISTORY
This is largely unknown. One study of such patients with a normal endoscopy found that symptoms spontaneously resolved in just over a third of patients. Follow-up studies show that organic disease is rarely diagnosed subsequently (6, 7). Cohort studies of symptom progression suggest that fewer than 10% of patients with functional dyspepsia are diagnosed with predominant reflux symptoms two years later and fewer than 5% with peptic ulcer disease (7). It is unclear whether this is higher than the rate of diagnosis of these diseases in the asymptomatic population. A study to evaluate this is needed.
4. MORBIDITY AND MORTALITY
Patients with functional dyspepsia have a normal life expectancy (8).
However the condition does account for a large amount of morbidity in the community, much of it hidden. Only about 1 in 4 people with dyspeptic symptoms choose to consult a physician. Nevertheless because of the high prevalence of the disease and the chronic or recurrent nature of symptoms functional dyspepsia is a clinical problem of considerable cost to the health care system.
5. ASSOCIATIONS
Functional dyspepsia is associated with irritable bowel syndrome with a third of patent with functional dyspepsia also reporting IBS symptoms (9).
6. AGE AND GENDER
There is no evidence for a difference in the prevalence of functional dyspepsia between men and women. Few studies have analysed the prevalence of dyspepsia by age but some data report a fall in the prevalence of reported symptoms after the age of 50 years for both men and women (9, 10). Whether this correlates with a true fall in the prevalence of dyspepsia is unclear.
7. GEOGRAPHY
8. EFFECTS OF INTERVENTIONS
A number of interventions have been tried for the treatment of functional dyspepsia. These include psychological intervention, acid suppression therapy, H.pylori eradication and prokinetic therapy. The reported benefits for all these therapies have been small if any. A systematic review of studies of psychological intervention has shown no overall benefit (11). Anti- secretory therapy may be effective but the effect seen in randomized trials may have been due to the inclusion of patients with organic disease. H pylori eradication therapy has a small but statistically significant effect in H pylori positive functional dyspepsia that may make it cost-effective treatment but the issue has been subject to considerable debate (12, 13). Prokinetic therapy has a small benefit if at all and is expensive and generally poorly tolerated.
9. AETIOLOGY
The pathophysiology of functional dyspepsia is only partially elucidated.
However, there is growing evidence that functional dyspepsia is in fact a heterogeneous disorder. Several pathophysiologic mechanisms have been suggested. These include delayed gastric emptying (14), impaired gastric accommodation to a meal (15), hypersensitivity to gastric distension (16), H.
pylori infection (17), altered response to duodenal lipids or acid (18), abnormal motility (19), or central nervous system dysfunction. In these respects, it shows a lot of characteristics with the irritable bowel syndrome.
Also, like irritable bowel syndrome, in some cases the onset of dyspepsia may bebe related to an infectious cause (20).
There is no convincing evidence that the epidemiology of functional dyspepsia is changing, but data on the prevalence in the lesser developed world are minimal.
10. SUMMARY
Functional dyspepsia is a very common disorder in western society and a cause of considerable morbidity, much of it hidden. The cause is unknown and it may be a constellation of related disorders. Treatment, as a consequence, is most unsatisfactory, the evaluation being complicated by functional dyspepsia’s tendency to spontaneous resolution.
References
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20. Tack J, Demedts I, Dehondt G, et al. Clinical and pathophysiological characteristics of acute-onset functional dyspepsia. Gastroenterology 122,1738-47 (2002).
