The chronic upper-central abdominal discomfort or pain in a patient whose predominant symptom is not heartburn is typically considered to be functional dyspepsia. This diagnosis, however, is rather vague, because the symptoms often overlap with those of peptic ulcer, esophagitis, or irritable bowel syndrome.

Patients with functional dyspepsia typically do not respond well to the medications available to treat it. Yet many have periodic symptoms that erode their overall quality of life.

Rome II criteria suggest that patients with functional dyspepsia should be classified into subgroups based on the single most troublesome symptom, rather than on a collection of complaints, to help identify those with similar pathophysiology and clinical findings.

A new study published in Gastro­enterology (2006;130: 296-303), led by George Karamanolis, of the Center for Gastroenterological Re­search, Univer­sity Hospital Gasthuis­berg, Leuven, Belgium, evaluated the connection between predominant pain or discomfort in dyspepsia and the resulting functional changes to ­determine the utility of the Rome II ­subcategories.

Included were 720 consecutive pa­tients (489 women; mean age, 41.3 ± 0.6 years) with a diagnosis of functional dyspepsia. Each participant filled out a dyspepsia questionnaire and identified the single most predominant symptom. Investigators then assessed the relationship of this predominant symptom to demographic, clinical, and pathophysiologic features (ie, Helicobacter pylori status, gastric emptying in 592 patients, and gastric sensitivity and accommodation testing in 332 patients).

None of the patients reported problems discerning the difference be­tween pain and nonpain symptoms, and none had problems singling out the predominant symptom. The most frequently reported symptoms were postprandial fullness (24%) and epigastric pain (22%).

A total of 22% of the patients were classified as pain predominant, according to Rome II criteria, while 78% were discomfort predominant. The former were more likely to have hypersensitivity (44% vs 25%) and less likely to have delayed gastric emptying compared with the discomfort-predominant group (16% vs 25%). However, there was a substantial overlap between the groups. A comprehensive analysis of the data revealed that any of the 8 symptoms associated with functional dyspepsia (ie, epigastric pain, bloating, postprandial fullness, early satiety, nausea, vomiting, belching, and epigastric burning) could predominate in both the pain-predominant and discomfort-predominant groups when demographic, clinical, and pathophysiologic characteristics were taken into account.

Patients who re­ported early satiety or vomiting as the predominant symptom had higher prevalences of weight loss (89% and 75%, respectively) and acute onset (61% and 60%, respectively). More than three fourths (79%) of patients with predominant early satiety had impaired accommodation. In a summary of data that included demographic, clinical, and pathophysiologic features in patients according to the single predominant symptom, delayed emptying was reported most often in those with predominant fullness (38%) and those with hypersensitivity (44%).

Based on the substantial overlap in pathophysiologic irregularities between the 2 groups, and that the predominant symptom could not dependably classify a subgroup with a definite underlying irregularity of sensorimotor function, “it seems that the Rome II subdivision does not identify subgroups that are homogeneous enough to be clinically meaningful and useful,” the authors write.

In an accompanying editorial (pages 593-595), Michael Camilleri, MD, and Adil E. Bharucha, MBBS, MD, of the Mayo Clinic College of Medicine, Rochester, Minn, note that this study “essentially draws a blank,” as the assessment of predominant symptoms “does not allow greater prediction of mechanism in functional dyspepsia.”

Drs Camilleri and Bharucha point out 3 drawbacks of the study that may have contributed to the apparent lack of an association between predominant symptoms and risk factors or the ­pathophysiology:

• Additional potential predictors of the symptoms reported (eg, psychosocial dimensions, somatization) were not assessed.

• Making the patients choose 1 predominant symptom may have prejudiced the assessment of its connection to pathophysiology.

• The methods used to measure gastric tone and emptying were limited.

“One of the practical implications of this study is that clinicians should comprehensively characterize dyspeptic symptoms rather than focusing on the predominant symptom,” they write. However, they add that further study is needed.