Symptoms and Tests for Irritable Bowel Syndrome: Diagnosing a Complex Disorder

Use of symptom criteria for diagnosing irritable bowel syndrome (IBS) is complicated by issues concerning the selection of terms for nociceptive sensations, possible interaction of language with cognition, gender-based variation in pain description, language translation problems, bowel habit classification, and the role of bloating and abdominal distension, and other symptoms and factors. Limited symptom validation and extensive patient follow-up indicate that IBS symptom criteria are accurate. However, symptom overlap between constipation-predominant IBS and functional constipation occurs, and special tests are required to identify a functional defecation disorder. Fluctuating IBS symptoms and the complex pathophysiology could be associated with limited durability of some test abnormalities, including transit studies. Unnecessary testing has a negative impact on patient outcome. Most patients can be managed on the basis of symptoms.