The aims of this study were to: 1) determine the relative prevalence of self-reported pain-predominant and discomfort-predominant symptom patterns in irritable bowel syndrome (IBS) patients; and 2) test the hypotheses that pain-predominant patients report higher GI symptom severity, show higher psychological symptom severity, show worse quality of life, and demonstrate higher health care use.
A total of 256 consecutive ROME I-positive IBS patients with moderate to severe symptoms were classified according to whether they rated their predominant IBS symptoms as pain (n = 52), or as nonpainful discomfort (n = 128) on the Irritable Bowel Syndrome Quality of Life questionnaire. The validity of this classification scheme was confirmed by interview in a subsample of 45 patients. IBS-specific symptom patterns, psychometric assessment, and health-related quality of life measures were obtained using validated survey instruments.
Contrary to the generally accepted notion that pain is the most predominant symptom in IBS, twice as many patients self-classified their symptoms as abdominal discomfort rather than abdominal pain. The classifications based on questionnaire data were shown to be valid in a subsample of subjects (n = 45) who underwent classification based on an independent, blinded, clinical interview (r = 0.77, p < 0.05). Pain and discomfort subgroups were similar in age, gender, predominant bowel habit, and overall GI symptom severity. In addition, the subgroups reported similar degrees of psychological distress, impaired quality of life, and increased patterns of health care use.
Subgroups of moderate to severe IBS patients do report their predominant GI symptoms in terms of pain or nonpainful discomfort, regardless of severity of their overall GI symptoms or psychological symptoms. These findings are most consistent with a cognitive labeling bias of visceral sensations as either pain or discomfort.