Psychological factors affect IBS patients' interpretation of symptom severity

A patient's viewpoint of the severity of irritable bowel syndrome (IBS) symptoms can be influenced not only by physical symptoms of IBS but broader psychological problems, according to a new study in Clinical Gastroenterology and Hepatology, the official journal of the American Gastroenterological Association.

"Clinicians who face pressure to treat patients in a cost-effective manner within tight time constraints and at a satisfactory level are likely to find that patient-reported outcome data can increase their understanding of what patients mean when they describe how they function or feel," said Jeffrey Lackner, PsyD, of the University at Buffalo School of Medicine and Biomedical Sciences, and lead author of this study. "To maximize the utility of patient-reported outcomes, it is important to know what they measure and what influences patients' perceptions of their symptoms when gastroenterologists ask them about their symptoms. Our study suggests that irritable bowel syndrome patient-reported outcomes are not simply about gastrointestinal symptoms."

Patient-reported outcomes (PROs) are used to describe symptoms, inform treatment planning and gauge the benefit of treatments for gastrointestinal disorders, including IBS. In this study, funded by the National Institute of Diabetes and Digestive and Kidney Diseases, researchers explored two different PRO rating scales that measure IBS severity, and identified psychological factors that might bias PRO ratings by affecting how patients interpret symptom severity. They found that a substantial proportion of the variation in the PROs (50 to 55 percent) could be explained by three distinct gastrointestinal (GI) symptoms: pain, bloating and defecation.

While the study showed that GI symptoms explain some of the variance in overall IBS severity scores, there was a large proportion of variance that was not attributable to symptoms that may be explained by psychological factors. For example, pain catastrophisizing (the belief that pain is awful), somatization (converting distress into physical symptoms) and anxiety sensitivity (fear of arousal symptoms) had a direct association with GI symptoms, but not with overall IBS severity. This suggests that psychological factors affect severity through their impact on GI symptoms.

"The patient-reported outcome movement is likely, in the near future, to extend to clinical settings where a premium is placed on understanding symptoms from the patient's perspective. This is particularly true for IBS and other benign diseases that lack a biomarker marking illness severity. Our results show that the science of asking and answering questions is an inescapable, but potentially positive, step in the direction of understanding patients' symptoms," added Dr. Lackner.

IBS is a chronic, painful, oftentimes disabling GI condition that leads to crampy pain, gassiness, bloating and changes in bowel habits. Some people with IBS have constipation, others have diarrhea, and some people experience both. There is no satisfactory medical treatment for its full range of symptoms. To meet the unmet need for safe, effective and widely available treatments for IBS, the FDA issued a PRO guidance document. A PRO instrument is used to capture clinically important information regarding the therapeutic benefit of treatment from the patient's perspective.