Prospective diary evaluation of unexplained abdominal pain and bowel dysfunction: A population-based colonoscopy study

Introduction: Diagnostic criteria for irritable bowel syndrome (IBS) have not been validated by prospective symptom diary. We investigated the bowel patterns in community subjects with and without non-organic abdominal pain, and compared the symptoms with subjects fulfilling the Rome II criteria (IBS). Methods: From the Swedish population register, a random sample completed an abdominal symptom questionnaire. Responders were subsequently invited for a clinical evaluation and offered a colonoscopy regardless of whether they had abdominal symptoms or not. A total of 268 subjects underwent colonoscopy, clinical evaluation by gastroenterologist, laboratory investigations, and completed the Rome questionnaire and prospective gastrointestinal (GI) symptom diaries for 1 week. Twenty-three subjects of 268 were excluded due to organic GI disease. Results: Subjects recorded 2,194 bowel movements and 370 abdominal pain episodes on 1,504 days. Subjects with pain in the diary (n = 81) had higher stool frequency (P = 0.01), more urgency (P = 0.0002), feelings of incomplete evacuation (P = 0.0002), nausea (P = 0.0009), and abdominal bloating (P = 0.0005) than subjects without pain (n = 151). Twenty-eight subjects (12%) fulfilled the Rome II criteria for IBS. Together, they had 96 pain episodes but only 4% were improved by defecation; 29% of the pain episodes started or worsened after a meal. Subjects with IBS and other subjects with non-organic abdominal pain (n = 64) exhibited no differences in terms of the proportions of pain episodes improved by defecation, bloating, stool frequency, consistency, or defecatory symptoms. Conclusions: Current criteria for IBS that rely on recall of the relationship between abdominal pain and bowel disturbance may overcall this association when measured prospectively.